extensions are working! extensions are working!

1 files changed, 2080 insertions, 767 deletions

diff --git a/nexgb/xproto.go b/nexgb/xproto.go
index d56f0a1..32fa6dd 100644
--- a/nexgb/xproto.go
+++ b/nexgb/xproto.go
@@ -1,10 +1,16 @@
 package xgb
 
 /*
-	This file was generated by xproto.xml on May 5 2012 2:50:11am EDT.
+	This file was generated by xproto.xml on May 5 2012 5:43:45pm EDT.
 	This file is automatically generated. Edit at your peril!
 */
 
+// Skipping definition for base type 'Int32'
+
+// Skipping definition for base type 'Void'
+
+// Skipping definition for base type 'Byte'
+
 // Skipping definition for base type 'Int8'
 
 // Skipping definition for base type 'Card16'
@@ -25,12 +31,6 @@ package xgb
 
 // Skipping definition for base type 'Int16'
 
-// Skipping definition for base type 'Int32'
-
-// Skipping definition for base type 'Void'
-
-// Skipping definition for base type 'Byte'
-
 const (
 	VisualClassStaticGray  = 0
 	VisualClassGrayScale   = 1
@@ -2731,6 +2731,23 @@ func (v KeyPressEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v KeyPressEvent) String() string {
+	fieldVals := make([]string, 0, 12)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Detail: %d", v.Detail))
+	fieldVals = append(fieldVals, sprintf("Time: %d", v.Time))
+	fieldVals = append(fieldVals, sprintf("Root: %d", v.Root))
+	fieldVals = append(fieldVals, sprintf("Event: %d", v.Event))
+	fieldVals = append(fieldVals, sprintf("Child: %d", v.Child))
+	fieldVals = append(fieldVals, sprintf("RootX: %d", v.RootX))
+	fieldVals = append(fieldVals, sprintf("RootY: %d", v.RootY))
+	fieldVals = append(fieldVals, sprintf("EventX: %d", v.EventX))
+	fieldVals = append(fieldVals, sprintf("EventY: %d", v.EventY))
+	fieldVals = append(fieldVals, sprintf("State: %d", v.State))
+	fieldVals = append(fieldVals, sprintf("SameScreen: %t", v.SameScreen))
+	return "KeyPress {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[2] = NewKeyPressEvent
 }
@@ -2865,6 +2882,23 @@ func (v ButtonPressEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v ButtonPressEvent) String() string {
+	fieldVals := make([]string, 0, 12)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Detail: %d", v.Detail))
+	fieldVals = append(fieldVals, sprintf("Time: %d", v.Time))
+	fieldVals = append(fieldVals, sprintf("Root: %d", v.Root))
+	fieldVals = append(fieldVals, sprintf("Event: %d", v.Event))
+	fieldVals = append(fieldVals, sprintf("Child: %d", v.Child))
+	fieldVals = append(fieldVals, sprintf("RootX: %d", v.RootX))
+	fieldVals = append(fieldVals, sprintf("RootY: %d", v.RootY))
+	fieldVals = append(fieldVals, sprintf("EventX: %d", v.EventX))
+	fieldVals = append(fieldVals, sprintf("EventY: %d", v.EventY))
+	fieldVals = append(fieldVals, sprintf("State: %d", v.State))
+	fieldVals = append(fieldVals, sprintf("SameScreen: %t", v.SameScreen))
+	return "ButtonPress {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[4] = NewButtonPressEvent
 }
@@ -2999,6 +3033,23 @@ func (v MotionNotifyEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v MotionNotifyEvent) String() string {
+	fieldVals := make([]string, 0, 12)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Detail: %d", v.Detail))
+	fieldVals = append(fieldVals, sprintf("Time: %d", v.Time))
+	fieldVals = append(fieldVals, sprintf("Root: %d", v.Root))
+	fieldVals = append(fieldVals, sprintf("Event: %d", v.Event))
+	fieldVals = append(fieldVals, sprintf("Child: %d", v.Child))
+	fieldVals = append(fieldVals, sprintf("RootX: %d", v.RootX))
+	fieldVals = append(fieldVals, sprintf("RootY: %d", v.RootY))
+	fieldVals = append(fieldVals, sprintf("EventX: %d", v.EventX))
+	fieldVals = append(fieldVals, sprintf("EventY: %d", v.EventY))
+	fieldVals = append(fieldVals, sprintf("State: %d", v.State))
+	fieldVals = append(fieldVals, sprintf("SameScreen: %t", v.SameScreen))
+	return "MotionNotify {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[6] = NewMotionNotifyEvent
 }
@@ -3127,6 +3178,24 @@ func (v EnterNotifyEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v EnterNotifyEvent) String() string {
+	fieldVals := make([]string, 0, 12)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Detail: %d", v.Detail))
+	fieldVals = append(fieldVals, sprintf("Time: %d", v.Time))
+	fieldVals = append(fieldVals, sprintf("Root: %d", v.Root))
+	fieldVals = append(fieldVals, sprintf("Event: %d", v.Event))
+	fieldVals = append(fieldVals, sprintf("Child: %d", v.Child))
+	fieldVals = append(fieldVals, sprintf("RootX: %d", v.RootX))
+	fieldVals = append(fieldVals, sprintf("RootY: %d", v.RootY))
+	fieldVals = append(fieldVals, sprintf("EventX: %d", v.EventX))
+	fieldVals = append(fieldVals, sprintf("EventY: %d", v.EventY))
+	fieldVals = append(fieldVals, sprintf("State: %d", v.State))
+	fieldVals = append(fieldVals, sprintf("Mode: %d", v.Mode))
+	fieldVals = append(fieldVals, sprintf("SameScreenFocus: %d", v.SameScreenFocus))
+	return "EnterNotify {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[7] = NewEnterNotifyEvent
 }
@@ -3197,6 +3266,15 @@ func (v FocusInEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v FocusInEvent) String() string {
+	fieldVals := make([]string, 0, 4)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Detail: %d", v.Detail))
+	fieldVals = append(fieldVals, sprintf("Event: %d", v.Event))
+	fieldVals = append(fieldVals, sprintf("Mode: %d", v.Mode))
+	return "FocusIn {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[9] = NewFocusInEvent
 }
@@ -3243,6 +3321,11 @@ func (v KeymapNotifyEvent) SequenceId() uint16 {
 	return uint16(0)
 }
 
+func (v KeymapNotifyEvent) String() string {
+	fieldVals := make([]string, 0, 1)
+	return "KeymapNotify {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[11] = NewKeymapNotifyEvent
 }
@@ -3339,6 +3422,18 @@ func (v ExposeEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v ExposeEvent) String() string {
+	fieldVals := make([]string, 0, 8)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Window: %d", v.Window))
+	fieldVals = append(fieldVals, sprintf("X: %d", v.X))
+	fieldVals = append(fieldVals, sprintf("Y: %d", v.Y))
+	fieldVals = append(fieldVals, sprintf("Width: %d", v.Width))
+	fieldVals = append(fieldVals, sprintf("Height: %d", v.Height))
+	fieldVals = append(fieldVals, sprintf("Count: %d", v.Count))
+	return "Expose {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[12] = NewExposeEvent
 }
@@ -3449,6 +3544,20 @@ func (v GraphicsExposureEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v GraphicsExposureEvent) String() string {
+	fieldVals := make([]string, 0, 10)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Drawable: %d", v.Drawable))
+	fieldVals = append(fieldVals, sprintf("X: %d", v.X))
+	fieldVals = append(fieldVals, sprintf("Y: %d", v.Y))
+	fieldVals = append(fieldVals, sprintf("Width: %d", v.Width))
+	fieldVals = append(fieldVals, sprintf("Height: %d", v.Height))
+	fieldVals = append(fieldVals, sprintf("MinorOpcode: %d", v.MinorOpcode))
+	fieldVals = append(fieldVals, sprintf("Count: %d", v.Count))
+	fieldVals = append(fieldVals, sprintf("MajorOpcode: %d", v.MajorOpcode))
+	return "GraphicsExposure {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[13] = NewGraphicsExposureEvent
 }
@@ -3524,6 +3633,15 @@ func (v NoExposureEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v NoExposureEvent) String() string {
+	fieldVals := make([]string, 0, 5)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Drawable: %d", v.Drawable))
+	fieldVals = append(fieldVals, sprintf("MinorOpcode: %d", v.MinorOpcode))
+	fieldVals = append(fieldVals, sprintf("MajorOpcode: %d", v.MajorOpcode))
+	return "NoExposure {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[14] = NewNoExposureEvent
 }
@@ -3592,6 +3710,14 @@ func (v VisibilityNotifyEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v VisibilityNotifyEvent) String() string {
+	fieldVals := make([]string, 0, 4)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Window: %d", v.Window))
+	fieldVals = append(fieldVals, sprintf("State: %d", v.State))
+	return "VisibilityNotify {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[15] = NewVisibilityNotifyEvent
 }
@@ -3710,6 +3836,20 @@ func (v CreateNotifyEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v CreateNotifyEvent) String() string {
+	fieldVals := make([]string, 0, 10)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Parent: %d", v.Parent))
+	fieldVals = append(fieldVals, sprintf("Window: %d", v.Window))
+	fieldVals = append(fieldVals, sprintf("X: %d", v.X))
+	fieldVals = append(fieldVals, sprintf("Y: %d", v.Y))
+	fieldVals = append(fieldVals, sprintf("Width: %d", v.Width))
+	fieldVals = append(fieldVals, sprintf("Height: %d", v.Height))
+	fieldVals = append(fieldVals, sprintf("BorderWidth: %d", v.BorderWidth))
+	fieldVals = append(fieldVals, sprintf("OverrideRedirect: %t", v.OverrideRedirect))
+	return "CreateNotify {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[16] = NewCreateNotifyEvent
 }
@@ -3773,6 +3913,14 @@ func (v DestroyNotifyEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v DestroyNotifyEvent) String() string {
+	fieldVals := make([]string, 0, 3)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Event: %d", v.Event))
+	fieldVals = append(fieldVals, sprintf("Window: %d", v.Window))
+	return "DestroyNotify {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[17] = NewDestroyNotifyEvent
 }
@@ -3856,6 +4004,15 @@ func (v UnmapNotifyEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v UnmapNotifyEvent) String() string {
+	fieldVals := make([]string, 0, 5)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Event: %d", v.Event))
+	fieldVals = append(fieldVals, sprintf("Window: %d", v.Window))
+	fieldVals = append(fieldVals, sprintf("FromConfigure: %t", v.FromConfigure))
+	return "UnmapNotify {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[18] = NewUnmapNotifyEvent
 }
@@ -3939,6 +4096,15 @@ func (v MapNotifyEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v MapNotifyEvent) String() string {
+	fieldVals := make([]string, 0, 5)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Event: %d", v.Event))
+	fieldVals = append(fieldVals, sprintf("Window: %d", v.Window))
+	fieldVals = append(fieldVals, sprintf("OverrideRedirect: %t", v.OverrideRedirect))
+	return "MapNotify {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[19] = NewMapNotifyEvent
 }
@@ -4002,6 +4168,14 @@ func (v MapRequestEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v MapRequestEvent) String() string {
+	fieldVals := make([]string, 0, 3)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Parent: %d", v.Parent))
+	fieldVals = append(fieldVals, sprintf("Window: %d", v.Window))
+	return "MapRequest {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[20] = NewMapRequestEvent
 }
@@ -4106,6 +4280,18 @@ func (v ReparentNotifyEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v ReparentNotifyEvent) String() string {
+	fieldVals := make([]string, 0, 8)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Event: %d", v.Event))
+	fieldVals = append(fieldVals, sprintf("Window: %d", v.Window))
+	fieldVals = append(fieldVals, sprintf("Parent: %d", v.Parent))
+	fieldVals = append(fieldVals, sprintf("X: %d", v.X))
+	fieldVals = append(fieldVals, sprintf("Y: %d", v.Y))
+	fieldVals = append(fieldVals, sprintf("OverrideRedirect: %t", v.OverrideRedirect))
+	return "ReparentNotify {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[21] = NewReparentNotifyEvent
 }
@@ -4231,6 +4417,21 @@ func (v ConfigureNotifyEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v ConfigureNotifyEvent) String() string {
+	fieldVals := make([]string, 0, 11)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Event: %d", v.Event))
+	fieldVals = append(fieldVals, sprintf("Window: %d", v.Window))
+	fieldVals = append(fieldVals, sprintf("AboveSibling: %d", v.AboveSibling))
+	fieldVals = append(fieldVals, sprintf("X: %d", v.X))
+	fieldVals = append(fieldVals, sprintf("Y: %d", v.Y))
+	fieldVals = append(fieldVals, sprintf("Width: %d", v.Width))
+	fieldVals = append(fieldVals, sprintf("Height: %d", v.Height))
+	fieldVals = append(fieldVals, sprintf("BorderWidth: %d", v.BorderWidth))
+	fieldVals = append(fieldVals, sprintf("OverrideRedirect: %t", v.OverrideRedirect))
+	return "ConfigureNotify {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[22] = NewConfigureNotifyEvent
 }
@@ -4345,6 +4546,22 @@ func (v ConfigureRequestEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v ConfigureRequestEvent) String() string {
+	fieldVals := make([]string, 0, 10)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("StackMode: %d", v.StackMode))
+	fieldVals = append(fieldVals, sprintf("Parent: %d", v.Parent))
+	fieldVals = append(fieldVals, sprintf("Window: %d", v.Window))
+	fieldVals = append(fieldVals, sprintf("Sibling: %d", v.Sibling))
+	fieldVals = append(fieldVals, sprintf("X: %d", v.X))
+	fieldVals = append(fieldVals, sprintf("Y: %d", v.Y))
+	fieldVals = append(fieldVals, sprintf("Width: %d", v.Width))
+	fieldVals = append(fieldVals, sprintf("Height: %d", v.Height))
+	fieldVals = append(fieldVals, sprintf("BorderWidth: %d", v.BorderWidth))
+	fieldVals = append(fieldVals, sprintf("ValueMask: %d", v.ValueMask))
+	return "ConfigureRequest {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[23] = NewConfigureRequestEvent
 }
@@ -4422,6 +4639,16 @@ func (v GravityNotifyEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v GravityNotifyEvent) String() string {
+	fieldVals := make([]string, 0, 5)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Event: %d", v.Event))
+	fieldVals = append(fieldVals, sprintf("Window: %d", v.Window))
+	fieldVals = append(fieldVals, sprintf("X: %d", v.X))
+	fieldVals = append(fieldVals, sprintf("Y: %d", v.Y))
+	return "GravityNotify {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[24] = NewGravityNotifyEvent
 }
@@ -4492,6 +4719,15 @@ func (v ResizeRequestEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v ResizeRequestEvent) String() string {
+	fieldVals := make([]string, 0, 4)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Window: %d", v.Window))
+	fieldVals = append(fieldVals, sprintf("Width: %d", v.Width))
+	fieldVals = append(fieldVals, sprintf("Height: %d", v.Height))
+	return "ResizeRequest {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[25] = NewResizeRequestEvent
 }
@@ -4572,6 +4808,15 @@ func (v CirculateNotifyEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v CirculateNotifyEvent) String() string {
+	fieldVals := make([]string, 0, 6)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Event: %d", v.Event))
+	fieldVals = append(fieldVals, sprintf("Window: %d", v.Window))
+	fieldVals = append(fieldVals, sprintf("Place: %d", v.Place))
+	return "CirculateNotify {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[26] = NewCirculateNotifyEvent
 }
@@ -4654,6 +4899,16 @@ func (v PropertyNotifyEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v PropertyNotifyEvent) String() string {
+	fieldVals := make([]string, 0, 6)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Window: %d", v.Window))
+	fieldVals = append(fieldVals, sprintf("Atom: %d", v.Atom))
+	fieldVals = append(fieldVals, sprintf("Time: %d", v.Time))
+	fieldVals = append(fieldVals, sprintf("State: %d", v.State))
+	return "PropertyNotify {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[28] = NewPropertyNotifyEvent
 }
@@ -4724,6 +4979,15 @@ func (v SelectionClearEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v SelectionClearEvent) String() string {
+	fieldVals := make([]string, 0, 4)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Time: %d", v.Time))
+	fieldVals = append(fieldVals, sprintf("Owner: %d", v.Owner))
+	fieldVals = append(fieldVals, sprintf("Selection: %d", v.Selection))
+	return "SelectionClear {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[29] = NewSelectionClearEvent
 }
@@ -4815,6 +5079,18 @@ func (v SelectionRequestEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v SelectionRequestEvent) String() string {
+	fieldVals := make([]string, 0, 7)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Time: %d", v.Time))
+	fieldVals = append(fieldVals, sprintf("Owner: %d", v.Owner))
+	fieldVals = append(fieldVals, sprintf("Requestor: %d", v.Requestor))
+	fieldVals = append(fieldVals, sprintf("Selection: %d", v.Selection))
+	fieldVals = append(fieldVals, sprintf("Target: %d", v.Target))
+	fieldVals = append(fieldVals, sprintf("Property: %d", v.Property))
+	return "SelectionRequest {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[30] = NewSelectionRequestEvent
 }
@@ -4899,6 +5175,17 @@ func (v SelectionNotifyEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v SelectionNotifyEvent) String() string {
+	fieldVals := make([]string, 0, 6)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Time: %d", v.Time))
+	fieldVals = append(fieldVals, sprintf("Requestor: %d", v.Requestor))
+	fieldVals = append(fieldVals, sprintf("Selection: %d", v.Selection))
+	fieldVals = append(fieldVals, sprintf("Target: %d", v.Target))
+	fieldVals = append(fieldVals, sprintf("Property: %d", v.Property))
+	return "SelectionNotify {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[31] = NewSelectionNotifyEvent
 }
@@ -4989,6 +5276,16 @@ func (v ColormapNotifyEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v ColormapNotifyEvent) String() string {
+	fieldVals := make([]string, 0, 6)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Window: %d", v.Window))
+	fieldVals = append(fieldVals, sprintf("Colormap: %d", v.Colormap))
+	fieldVals = append(fieldVals, sprintf("New: %t", v.New))
+	fieldVals = append(fieldVals, sprintf("State: %d", v.State))
+	return "ColormapNotify {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[32] = NewColormapNotifyEvent
 }
@@ -5064,6 +5361,15 @@ func (v ClientMessageEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v ClientMessageEvent) String() string {
+	fieldVals := make([]string, 0, 4)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Format: %d", v.Format))
+	fieldVals = append(fieldVals, sprintf("Window: %d", v.Window))
+	fieldVals = append(fieldVals, sprintf("Type: %d", v.Type))
+	return "ClientMessage {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[33] = NewClientMessageEvent
 }
@@ -5139,6 +5445,15 @@ func (v MappingNotifyEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v MappingNotifyEvent) String() string {
+	fieldVals := make([]string, 0, 5)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Request: %d", v.Request))
+	fieldVals = append(fieldVals, sprintf("FirstKeycode: %d", v.FirstKeycode))
+	fieldVals = append(fieldVals, sprintf("Count: %d", v.Count))
+	return "MappingNotify {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[34] = NewMappingNotifyEvent
 }
@@ -5163,6 +5478,23 @@ func (v KeyReleaseEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v KeyReleaseEvent) String() string {
+	fieldVals := make([]string, 0, 12)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Detail: %d", v.Detail))
+	fieldVals = append(fieldVals, sprintf("Time: %d", v.Time))
+	fieldVals = append(fieldVals, sprintf("Root: %d", v.Root))
+	fieldVals = append(fieldVals, sprintf("Event: %d", v.Event))
+	fieldVals = append(fieldVals, sprintf("Child: %d", v.Child))
+	fieldVals = append(fieldVals, sprintf("RootX: %d", v.RootX))
+	fieldVals = append(fieldVals, sprintf("RootY: %d", v.RootY))
+	fieldVals = append(fieldVals, sprintf("EventX: %d", v.EventX))
+	fieldVals = append(fieldVals, sprintf("EventY: %d", v.EventY))
+	fieldVals = append(fieldVals, sprintf("State: %d", v.State))
+	fieldVals = append(fieldVals, sprintf("SameScreen: %t", v.SameScreen))
+	return "KeyRelease {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[3] = NewKeyReleaseEvent
 }
@@ -5187,6 +5519,23 @@ func (v ButtonReleaseEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v ButtonReleaseEvent) String() string {
+	fieldVals := make([]string, 0, 12)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Detail: %d", v.Detail))
+	fieldVals = append(fieldVals, sprintf("Time: %d", v.Time))
+	fieldVals = append(fieldVals, sprintf("Root: %d", v.Root))
+	fieldVals = append(fieldVals, sprintf("Event: %d", v.Event))
+	fieldVals = append(fieldVals, sprintf("Child: %d", v.Child))
+	fieldVals = append(fieldVals, sprintf("RootX: %d", v.RootX))
+	fieldVals = append(fieldVals, sprintf("RootY: %d", v.RootY))
+	fieldVals = append(fieldVals, sprintf("EventX: %d", v.EventX))
+	fieldVals = append(fieldVals, sprintf("EventY: %d", v.EventY))
+	fieldVals = append(fieldVals, sprintf("State: %d", v.State))
+	fieldVals = append(fieldVals, sprintf("SameScreen: %t", v.SameScreen))
+	return "ButtonRelease {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[5] = NewButtonReleaseEvent
 }
@@ -5211,6 +5560,24 @@ func (v LeaveNotifyEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v LeaveNotifyEvent) String() string {
+	fieldVals := make([]string, 0, 12)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Detail: %d", v.Detail))
+	fieldVals = append(fieldVals, sprintf("Time: %d", v.Time))
+	fieldVals = append(fieldVals, sprintf("Root: %d", v.Root))
+	fieldVals = append(fieldVals, sprintf("Event: %d", v.Event))
+	fieldVals = append(fieldVals, sprintf("Child: %d", v.Child))
+	fieldVals = append(fieldVals, sprintf("RootX: %d", v.RootX))
+	fieldVals = append(fieldVals, sprintf("RootY: %d", v.RootY))
+	fieldVals = append(fieldVals, sprintf("EventX: %d", v.EventX))
+	fieldVals = append(fieldVals, sprintf("EventY: %d", v.EventY))
+	fieldVals = append(fieldVals, sprintf("State: %d", v.State))
+	fieldVals = append(fieldVals, sprintf("Mode: %d", v.Mode))
+	fieldVals = append(fieldVals, sprintf("SameScreenFocus: %d", v.SameScreenFocus))
+	return "LeaveNotify {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[8] = NewLeaveNotifyEvent
 }
@@ -5235,6 +5602,15 @@ func (v FocusOutEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v FocusOutEvent) String() string {
+	fieldVals := make([]string, 0, 4)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Detail: %d", v.Detail))
+	fieldVals = append(fieldVals, sprintf("Event: %d", v.Event))
+	fieldVals = append(fieldVals, sprintf("Mode: %d", v.Mode))
+	return "FocusOut {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[10] = NewFocusOutEvent
 }
@@ -5259,6 +5635,15 @@ func (v CirculateRequestEvent) SequenceId() uint16 {
 	return v.Sequence
 }
 
+func (v CirculateRequestEvent) String() string {
+	fieldVals := make([]string, 0, 6)
+	fieldVals = append(fieldVals, sprintf("Sequence: %d", v.Sequence))
+	fieldVals = append(fieldVals, sprintf("Event: %d", v.Event))
+	fieldVals = append(fieldVals, sprintf("Window: %d", v.Window))
+	fieldVals = append(fieldVals, sprintf("Place: %d", v.Place))
+	return "CirculateRequest {" + stringsJoin(fieldVals, ", ") + "}"
+}
+
 func init() {
 	newEventFuncs[27] = NewCirculateRequestEvent
 }
@@ -5931,23 +6316,29 @@ func init() {
 
 // Request CreateWindow
 // size: pad((28 + (4 + pad((4 * popCount(int(ValueMask)))))))
-type CreateWindowCookie cookie
+type CreateWindowCookie struct {
+	*cookie
+}
 
 // Write request to wire for CreateWindow
 func (c *Conn) CreateWindow(Depth byte, Wid Id, Parent Id, X int16, Y int16, Width uint16, Height uint16, BorderWidth uint16, Class uint16, Visual Visualid, ValueMask uint32, ValueList []uint32) CreateWindowCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(createWindowRequest(Depth, Wid, Parent, X, Y, Width, Height, BorderWidth, Class, Visual, ValueMask, ValueList), cookie)
-	return CreateWindowCookie(cookie)
+	c.newRequest(c.createWindowRequest(Depth, Wid, Parent, X, Y, Width, Height, BorderWidth, Class, Visual, ValueMask, ValueList), cookie)
+	return CreateWindowCookie{cookie}
 }
 
 func (c *Conn) CreateWindowChecked(Depth byte, Wid Id, Parent Id, X int16, Y int16, Width uint16, Height uint16, BorderWidth uint16, Class uint16, Visual Visualid, ValueMask uint32, ValueList []uint32) CreateWindowCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(createWindowRequest(Depth, Wid, Parent, X, Y, Width, Height, BorderWidth, Class, Visual, ValueMask, ValueList), cookie)
-	return CreateWindowCookie(cookie)
+	c.newRequest(c.createWindowRequest(Depth, Wid, Parent, X, Y, Width, Height, BorderWidth, Class, Visual, ValueMask, ValueList), cookie)
+	return CreateWindowCookie{cookie}
+}
+
+func (cook CreateWindowCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for CreateWindow
-func createWindowRequest(Depth byte, Wid Id, Parent Id, X int16, Y int16, Width uint16, Height uint16, BorderWidth uint16, Class uint16, Visual Visualid, ValueMask uint32, ValueList []uint32) []byte {
+func (c *Conn) createWindowRequest(Depth byte, Wid Id, Parent Id, X int16, Y int16, Width uint16, Height uint16, BorderWidth uint16, Class uint16, Visual Visualid, ValueMask uint32, ValueList []uint32) []byte {
 	size := pad((28 + (4 + pad((4 * popCount(int(ValueMask)))))))
 	b := 0
 	buf := make([]byte, size)
@@ -6001,23 +6392,29 @@ func createWindowRequest(Depth byte, Wid Id, Parent Id, X int16, Y int16, Width
 
 // Request ChangeWindowAttributes
 // size: pad((8 + (4 + pad((4 * popCount(int(ValueMask)))))))
-type ChangeWindowAttributesCookie cookie
+type ChangeWindowAttributesCookie struct {
+	*cookie
+}
 
 // Write request to wire for ChangeWindowAttributes
 func (c *Conn) ChangeWindowAttributes(Window Id, ValueMask uint32, ValueList []uint32) ChangeWindowAttributesCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(changeWindowAttributesRequest(Window, ValueMask, ValueList), cookie)
-	return ChangeWindowAttributesCookie(cookie)
+	c.newRequest(c.changeWindowAttributesRequest(Window, ValueMask, ValueList), cookie)
+	return ChangeWindowAttributesCookie{cookie}
 }
 
 func (c *Conn) ChangeWindowAttributesChecked(Window Id, ValueMask uint32, ValueList []uint32) ChangeWindowAttributesCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(changeWindowAttributesRequest(Window, ValueMask, ValueList), cookie)
-	return ChangeWindowAttributesCookie(cookie)
+	c.newRequest(c.changeWindowAttributesRequest(Window, ValueMask, ValueList), cookie)
+	return ChangeWindowAttributesCookie{cookie}
+}
+
+func (cook ChangeWindowAttributesCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for ChangeWindowAttributes
-func changeWindowAttributesRequest(Window Id, ValueMask uint32, ValueList []uint32) []byte {
+func (c *Conn) changeWindowAttributesRequest(Window Id, ValueMask uint32, ValueList []uint32) []byte {
 	size := pad((8 + (4 + pad((4 * popCount(int(ValueMask)))))))
 	b := 0
 	buf := make([]byte, size)
@@ -6046,18 +6443,20 @@ func changeWindowAttributesRequest(Window Id, ValueMask uint32, ValueList []uint
 
 // Request GetWindowAttributes
 // size: 8
-type GetWindowAttributesCookie cookie
+type GetWindowAttributesCookie struct {
+	*cookie
+}
 
 func (c *Conn) GetWindowAttributes(Window Id) GetWindowAttributesCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(getWindowAttributesRequest(Window), cookie)
-	return GetWindowAttributesCookie(cookie)
+	c.newRequest(c.getWindowAttributesRequest(Window), cookie)
+	return GetWindowAttributesCookie{cookie}
 }
 
 func (c *Conn) GetWindowAttributesUnchecked(Window Id) GetWindowAttributesCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(getWindowAttributesRequest(Window), cookie)
-	return GetWindowAttributesCookie(cookie)
+	c.newRequest(c.getWindowAttributesRequest(Window), cookie)
+	return GetWindowAttributesCookie{cookie}
 }
 
 // Request reply for GetWindowAttributes
@@ -6085,10 +6484,13 @@ type GetWindowAttributesReply struct {
 
 // Waits and reads reply data from request GetWindowAttributes
 func (cook GetWindowAttributesCookie) Reply() (*GetWindowAttributesReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return getWindowAttributesReply(buf), nil
 }
 
@@ -6165,8 +6567,12 @@ func getWindowAttributesReply(buf []byte) *GetWindowAttributesReply {
 	return v
 }
 
+func (cook GetWindowAttributesCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for GetWindowAttributes
-func getWindowAttributesRequest(Window Id) []byte {
+func (c *Conn) getWindowAttributesRequest(Window Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -6187,23 +6593,29 @@ func getWindowAttributesRequest(Window Id) []byte {
 
 // Request DestroyWindow
 // size: 8
-type DestroyWindowCookie cookie
+type DestroyWindowCookie struct {
+	*cookie
+}
 
 // Write request to wire for DestroyWindow
 func (c *Conn) DestroyWindow(Window Id) DestroyWindowCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(destroyWindowRequest(Window), cookie)
-	return DestroyWindowCookie(cookie)
+	c.newRequest(c.destroyWindowRequest(Window), cookie)
+	return DestroyWindowCookie{cookie}
 }
 
 func (c *Conn) DestroyWindowChecked(Window Id) DestroyWindowCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(destroyWindowRequest(Window), cookie)
-	return DestroyWindowCookie(cookie)
+	c.newRequest(c.destroyWindowRequest(Window), cookie)
+	return DestroyWindowCookie{cookie}
+}
+
+func (cook DestroyWindowCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for DestroyWindow
-func destroyWindowRequest(Window Id) []byte {
+func (c *Conn) destroyWindowRequest(Window Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -6224,23 +6636,29 @@ func destroyWindowRequest(Window Id) []byte {
 
 // Request DestroySubwindows
 // size: 8
-type DestroySubwindowsCookie cookie
+type DestroySubwindowsCookie struct {
+	*cookie
+}
 
 // Write request to wire for DestroySubwindows
 func (c *Conn) DestroySubwindows(Window Id) DestroySubwindowsCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(destroySubwindowsRequest(Window), cookie)
-	return DestroySubwindowsCookie(cookie)
+	c.newRequest(c.destroySubwindowsRequest(Window), cookie)
+	return DestroySubwindowsCookie{cookie}
 }
 
 func (c *Conn) DestroySubwindowsChecked(Window Id) DestroySubwindowsCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(destroySubwindowsRequest(Window), cookie)
-	return DestroySubwindowsCookie(cookie)
+	c.newRequest(c.destroySubwindowsRequest(Window), cookie)
+	return DestroySubwindowsCookie{cookie}
+}
+
+func (cook DestroySubwindowsCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for DestroySubwindows
-func destroySubwindowsRequest(Window Id) []byte {
+func (c *Conn) destroySubwindowsRequest(Window Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -6261,23 +6679,29 @@ func destroySubwindowsRequest(Window Id) []byte {
 
 // Request ChangeSaveSet
 // size: 8
-type ChangeSaveSetCookie cookie
+type ChangeSaveSetCookie struct {
+	*cookie
+}
 
 // Write request to wire for ChangeSaveSet
 func (c *Conn) ChangeSaveSet(Mode byte, Window Id) ChangeSaveSetCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(changeSaveSetRequest(Mode, Window), cookie)
-	return ChangeSaveSetCookie(cookie)
+	c.newRequest(c.changeSaveSetRequest(Mode, Window), cookie)
+	return ChangeSaveSetCookie{cookie}
 }
 
 func (c *Conn) ChangeSaveSetChecked(Mode byte, Window Id) ChangeSaveSetCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(changeSaveSetRequest(Mode, Window), cookie)
-	return ChangeSaveSetCookie(cookie)
+	c.newRequest(c.changeSaveSetRequest(Mode, Window), cookie)
+	return ChangeSaveSetCookie{cookie}
+}
+
+func (cook ChangeSaveSetCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for ChangeSaveSet
-func changeSaveSetRequest(Mode byte, Window Id) []byte {
+func (c *Conn) changeSaveSetRequest(Mode byte, Window Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -6299,23 +6723,29 @@ func changeSaveSetRequest(Mode byte, Window Id) []byte {
 
 // Request ReparentWindow
 // size: 16
-type ReparentWindowCookie cookie
+type ReparentWindowCookie struct {
+	*cookie
+}
 
 // Write request to wire for ReparentWindow
 func (c *Conn) ReparentWindow(Window Id, Parent Id, X int16, Y int16) ReparentWindowCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(reparentWindowRequest(Window, Parent, X, Y), cookie)
-	return ReparentWindowCookie(cookie)
+	c.newRequest(c.reparentWindowRequest(Window, Parent, X, Y), cookie)
+	return ReparentWindowCookie{cookie}
 }
 
 func (c *Conn) ReparentWindowChecked(Window Id, Parent Id, X int16, Y int16) ReparentWindowCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(reparentWindowRequest(Window, Parent, X, Y), cookie)
-	return ReparentWindowCookie(cookie)
+	c.newRequest(c.reparentWindowRequest(Window, Parent, X, Y), cookie)
+	return ReparentWindowCookie{cookie}
+}
+
+func (cook ReparentWindowCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for ReparentWindow
-func reparentWindowRequest(Window Id, Parent Id, X int16, Y int16) []byte {
+func (c *Conn) reparentWindowRequest(Window Id, Parent Id, X int16, Y int16) []byte {
 	size := 16
 	b := 0
 	buf := make([]byte, size)
@@ -6345,23 +6775,29 @@ func reparentWindowRequest(Window Id, Parent Id, X int16, Y int16) []byte {
 
 // Request MapWindow
 // size: 8
-type MapWindowCookie cookie
+type MapWindowCookie struct {
+	*cookie
+}
 
 // Write request to wire for MapWindow
 func (c *Conn) MapWindow(Window Id) MapWindowCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(mapWindowRequest(Window), cookie)
-	return MapWindowCookie(cookie)
+	c.newRequest(c.mapWindowRequest(Window), cookie)
+	return MapWindowCookie{cookie}
 }
 
 func (c *Conn) MapWindowChecked(Window Id) MapWindowCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(mapWindowRequest(Window), cookie)
-	return MapWindowCookie(cookie)
+	c.newRequest(c.mapWindowRequest(Window), cookie)
+	return MapWindowCookie{cookie}
+}
+
+func (cook MapWindowCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for MapWindow
-func mapWindowRequest(Window Id) []byte {
+func (c *Conn) mapWindowRequest(Window Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -6382,23 +6818,29 @@ func mapWindowRequest(Window Id) []byte {
 
 // Request MapSubwindows
 // size: 8
-type MapSubwindowsCookie cookie
+type MapSubwindowsCookie struct {
+	*cookie
+}
 
 // Write request to wire for MapSubwindows
 func (c *Conn) MapSubwindows(Window Id) MapSubwindowsCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(mapSubwindowsRequest(Window), cookie)
-	return MapSubwindowsCookie(cookie)
+	c.newRequest(c.mapSubwindowsRequest(Window), cookie)
+	return MapSubwindowsCookie{cookie}
 }
 
 func (c *Conn) MapSubwindowsChecked(Window Id) MapSubwindowsCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(mapSubwindowsRequest(Window), cookie)
-	return MapSubwindowsCookie(cookie)
+	c.newRequest(c.mapSubwindowsRequest(Window), cookie)
+	return MapSubwindowsCookie{cookie}
+}
+
+func (cook MapSubwindowsCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for MapSubwindows
-func mapSubwindowsRequest(Window Id) []byte {
+func (c *Conn) mapSubwindowsRequest(Window Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -6419,23 +6861,29 @@ func mapSubwindowsRequest(Window Id) []byte {
 
 // Request UnmapWindow
 // size: 8
-type UnmapWindowCookie cookie
+type UnmapWindowCookie struct {
+	*cookie
+}
 
 // Write request to wire for UnmapWindow
 func (c *Conn) UnmapWindow(Window Id) UnmapWindowCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(unmapWindowRequest(Window), cookie)
-	return UnmapWindowCookie(cookie)
+	c.newRequest(c.unmapWindowRequest(Window), cookie)
+	return UnmapWindowCookie{cookie}
 }
 
 func (c *Conn) UnmapWindowChecked(Window Id) UnmapWindowCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(unmapWindowRequest(Window), cookie)
-	return UnmapWindowCookie(cookie)
+	c.newRequest(c.unmapWindowRequest(Window), cookie)
+	return UnmapWindowCookie{cookie}
+}
+
+func (cook UnmapWindowCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for UnmapWindow
-func unmapWindowRequest(Window Id) []byte {
+func (c *Conn) unmapWindowRequest(Window Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -6456,23 +6904,29 @@ func unmapWindowRequest(Window Id) []byte {
 
 // Request UnmapSubwindows
 // size: 8
-type UnmapSubwindowsCookie cookie
+type UnmapSubwindowsCookie struct {
+	*cookie
+}
 
 // Write request to wire for UnmapSubwindows
 func (c *Conn) UnmapSubwindows(Window Id) UnmapSubwindowsCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(unmapSubwindowsRequest(Window), cookie)
-	return UnmapSubwindowsCookie(cookie)
+	c.newRequest(c.unmapSubwindowsRequest(Window), cookie)
+	return UnmapSubwindowsCookie{cookie}
 }
 
 func (c *Conn) UnmapSubwindowsChecked(Window Id) UnmapSubwindowsCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(unmapSubwindowsRequest(Window), cookie)
-	return UnmapSubwindowsCookie(cookie)
+	c.newRequest(c.unmapSubwindowsRequest(Window), cookie)
+	return UnmapSubwindowsCookie{cookie}
+}
+
+func (cook UnmapSubwindowsCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for UnmapSubwindows
-func unmapSubwindowsRequest(Window Id) []byte {
+func (c *Conn) unmapSubwindowsRequest(Window Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -6493,23 +6947,29 @@ func unmapSubwindowsRequest(Window Id) []byte {
 
 // Request ConfigureWindow
 // size: pad((10 + (2 + pad((4 * popCount(int(ValueMask)))))))
-type ConfigureWindowCookie cookie
+type ConfigureWindowCookie struct {
+	*cookie
+}
 
 // Write request to wire for ConfigureWindow
 func (c *Conn) ConfigureWindow(Window Id, ValueMask uint16, ValueList []uint32) ConfigureWindowCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(configureWindowRequest(Window, ValueMask, ValueList), cookie)
-	return ConfigureWindowCookie(cookie)
+	c.newRequest(c.configureWindowRequest(Window, ValueMask, ValueList), cookie)
+	return ConfigureWindowCookie{cookie}
 }
 
 func (c *Conn) ConfigureWindowChecked(Window Id, ValueMask uint16, ValueList []uint32) ConfigureWindowCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(configureWindowRequest(Window, ValueMask, ValueList), cookie)
-	return ConfigureWindowCookie(cookie)
+	c.newRequest(c.configureWindowRequest(Window, ValueMask, ValueList), cookie)
+	return ConfigureWindowCookie{cookie}
+}
+
+func (cook ConfigureWindowCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for ConfigureWindow
-func configureWindowRequest(Window Id, ValueMask uint16, ValueList []uint32) []byte {
+func (c *Conn) configureWindowRequest(Window Id, ValueMask uint16, ValueList []uint32) []byte {
 	size := pad((10 + (2 + pad((4 * popCount(int(ValueMask)))))))
 	b := 0
 	buf := make([]byte, size)
@@ -6541,23 +7001,29 @@ func configureWindowRequest(Window Id, ValueMask uint16, ValueList []uint32) []b
 
 // Request CirculateWindow
 // size: 8
-type CirculateWindowCookie cookie
+type CirculateWindowCookie struct {
+	*cookie
+}
 
 // Write request to wire for CirculateWindow
 func (c *Conn) CirculateWindow(Direction byte, Window Id) CirculateWindowCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(circulateWindowRequest(Direction, Window), cookie)
-	return CirculateWindowCookie(cookie)
+	c.newRequest(c.circulateWindowRequest(Direction, Window), cookie)
+	return CirculateWindowCookie{cookie}
 }
 
 func (c *Conn) CirculateWindowChecked(Direction byte, Window Id) CirculateWindowCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(circulateWindowRequest(Direction, Window), cookie)
-	return CirculateWindowCookie(cookie)
+	c.newRequest(c.circulateWindowRequest(Direction, Window), cookie)
+	return CirculateWindowCookie{cookie}
+}
+
+func (cook CirculateWindowCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for CirculateWindow
-func circulateWindowRequest(Direction byte, Window Id) []byte {
+func (c *Conn) circulateWindowRequest(Direction byte, Window Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -6579,18 +7045,20 @@ func circulateWindowRequest(Direction byte, Window Id) []byte {
 
 // Request GetGeometry
 // size: 8
-type GetGeometryCookie cookie
+type GetGeometryCookie struct {
+	*cookie
+}
 
 func (c *Conn) GetGeometry(Drawable Id) GetGeometryCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(getGeometryRequest(Drawable), cookie)
-	return GetGeometryCookie(cookie)
+	c.newRequest(c.getGeometryRequest(Drawable), cookie)
+	return GetGeometryCookie{cookie}
 }
 
 func (c *Conn) GetGeometryUnchecked(Drawable Id) GetGeometryCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(getGeometryRequest(Drawable), cookie)
-	return GetGeometryCookie(cookie)
+	c.newRequest(c.getGeometryRequest(Drawable), cookie)
+	return GetGeometryCookie{cookie}
 }
 
 // Request reply for GetGeometry
@@ -6610,10 +7078,13 @@ type GetGeometryReply struct {
 
 // Waits and reads reply data from request GetGeometry
 func (cook GetGeometryCookie) Reply() (*GetGeometryReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return getGeometryReply(buf), nil
 }
 
@@ -6654,8 +7125,12 @@ func getGeometryReply(buf []byte) *GetGeometryReply {
 	return v
 }
 
+func (cook GetGeometryCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for GetGeometry
-func getGeometryRequest(Drawable Id) []byte {
+func (c *Conn) getGeometryRequest(Drawable Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -6676,18 +7151,20 @@ func getGeometryRequest(Drawable Id) []byte {
 
 // Request QueryTree
 // size: 8
-type QueryTreeCookie cookie
+type QueryTreeCookie struct {
+	*cookie
+}
 
 func (c *Conn) QueryTree(Window Id) QueryTreeCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(queryTreeRequest(Window), cookie)
-	return QueryTreeCookie(cookie)
+	c.newRequest(c.queryTreeRequest(Window), cookie)
+	return QueryTreeCookie{cookie}
 }
 
 func (c *Conn) QueryTreeUnchecked(Window Id) QueryTreeCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(queryTreeRequest(Window), cookie)
-	return QueryTreeCookie(cookie)
+	c.newRequest(c.queryTreeRequest(Window), cookie)
+	return QueryTreeCookie{cookie}
 }
 
 // Request reply for QueryTree
@@ -6705,10 +7182,13 @@ type QueryTreeReply struct {
 
 // Waits and reads reply data from request QueryTree
 func (cook QueryTreeCookie) Reply() (*QueryTreeReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return queryTreeReply(buf), nil
 }
 
@@ -6746,8 +7226,12 @@ func queryTreeReply(buf []byte) *QueryTreeReply {
 	return v
 }
 
+func (cook QueryTreeCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for QueryTree
-func queryTreeRequest(Window Id) []byte {
+func (c *Conn) queryTreeRequest(Window Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -6768,18 +7252,20 @@ func queryTreeRequest(Window Id) []byte {
 
 // Request InternAtom
 // size: pad((8 + pad((int(NameLen) * 1))))
-type InternAtomCookie cookie
+type InternAtomCookie struct {
+	*cookie
+}
 
 func (c *Conn) InternAtom(OnlyIfExists bool, NameLen uint16, Name string) InternAtomCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(internAtomRequest(OnlyIfExists, NameLen, Name), cookie)
-	return InternAtomCookie(cookie)
+	c.newRequest(c.internAtomRequest(OnlyIfExists, NameLen, Name), cookie)
+	return InternAtomCookie{cookie}
 }
 
 func (c *Conn) InternAtomUnchecked(OnlyIfExists bool, NameLen uint16, Name string) InternAtomCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(internAtomRequest(OnlyIfExists, NameLen, Name), cookie)
-	return InternAtomCookie(cookie)
+	c.newRequest(c.internAtomRequest(OnlyIfExists, NameLen, Name), cookie)
+	return InternAtomCookie{cookie}
 }
 
 // Request reply for InternAtom
@@ -6793,10 +7279,13 @@ type InternAtomReply struct {
 
 // Waits and reads reply data from request InternAtom
 func (cook InternAtomCookie) Reply() (*InternAtomReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return internAtomReply(buf), nil
 }
 
@@ -6819,8 +7308,12 @@ func internAtomReply(buf []byte) *InternAtomReply {
 	return v
 }
 
+func (cook InternAtomCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for InternAtom
-func internAtomRequest(OnlyIfExists bool, NameLen uint16, Name string) []byte {
+func (c *Conn) internAtomRequest(OnlyIfExists bool, NameLen uint16, Name string) []byte {
 	size := pad((8 + pad((int(NameLen) * 1))))
 	b := 0
 	buf := make([]byte, size)
@@ -6851,18 +7344,20 @@ func internAtomRequest(OnlyIfExists bool, NameLen uint16, Name string) []byte {
 
 // Request GetAtomName
 // size: 8
-type GetAtomNameCookie cookie
+type GetAtomNameCookie struct {
+	*cookie
+}
 
 func (c *Conn) GetAtomName(Atom Id) GetAtomNameCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(getAtomNameRequest(Atom), cookie)
-	return GetAtomNameCookie(cookie)
+	c.newRequest(c.getAtomNameRequest(Atom), cookie)
+	return GetAtomNameCookie{cookie}
 }
 
 func (c *Conn) GetAtomNameUnchecked(Atom Id) GetAtomNameCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(getAtomNameRequest(Atom), cookie)
-	return GetAtomNameCookie(cookie)
+	c.newRequest(c.getAtomNameRequest(Atom), cookie)
+	return GetAtomNameCookie{cookie}
 }
 
 // Request reply for GetAtomName
@@ -6878,10 +7373,13 @@ type GetAtomNameReply struct {
 
 // Waits and reads reply data from request GetAtomName
 func (cook GetAtomNameCookie) Reply() (*GetAtomNameReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return getAtomNameReply(buf), nil
 }
 
@@ -6913,8 +7411,12 @@ func getAtomNameReply(buf []byte) *GetAtomNameReply {
 	return v
 }
 
+func (cook GetAtomNameCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for GetAtomName
-func getAtomNameRequest(Atom Id) []byte {
+func (c *Conn) getAtomNameRequest(Atom Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -6935,23 +7437,29 @@ func getAtomNameRequest(Atom Id) []byte {
 
 // Request ChangeProperty
 // size: pad((24 + pad((((int(DataLen) * int(Format)) / 8) * 1))))
-type ChangePropertyCookie cookie
+type ChangePropertyCookie struct {
+	*cookie
+}
 
 // Write request to wire for ChangeProperty
 func (c *Conn) ChangeProperty(Mode byte, Window Id, Property Id, Type Id, Format byte, DataLen uint32, Data []byte) ChangePropertyCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(changePropertyRequest(Mode, Window, Property, Type, Format, DataLen, Data), cookie)
-	return ChangePropertyCookie(cookie)
+	c.newRequest(c.changePropertyRequest(Mode, Window, Property, Type, Format, DataLen, Data), cookie)
+	return ChangePropertyCookie{cookie}
 }
 
 func (c *Conn) ChangePropertyChecked(Mode byte, Window Id, Property Id, Type Id, Format byte, DataLen uint32, Data []byte) ChangePropertyCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(changePropertyRequest(Mode, Window, Property, Type, Format, DataLen, Data), cookie)
-	return ChangePropertyCookie(cookie)
+	c.newRequest(c.changePropertyRequest(Mode, Window, Property, Type, Format, DataLen, Data), cookie)
+	return ChangePropertyCookie{cookie}
+}
+
+func (cook ChangePropertyCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for ChangeProperty
-func changePropertyRequest(Mode byte, Window Id, Property Id, Type Id, Format byte, DataLen uint32, Data []byte) []byte {
+func (c *Conn) changePropertyRequest(Mode byte, Window Id, Property Id, Type Id, Format byte, DataLen uint32, Data []byte) []byte {
 	size := pad((24 + pad((((int(DataLen) * int(Format)) / 8) * 1))))
 	b := 0
 	buf := make([]byte, size)
@@ -6990,23 +7498,29 @@ func changePropertyRequest(Mode byte, Window Id, Property Id, Type Id, Format by
 
 // Request DeleteProperty
 // size: 12
-type DeletePropertyCookie cookie
+type DeletePropertyCookie struct {
+	*cookie
+}
 
 // Write request to wire for DeleteProperty
 func (c *Conn) DeleteProperty(Window Id, Property Id) DeletePropertyCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(deletePropertyRequest(Window, Property), cookie)
-	return DeletePropertyCookie(cookie)
+	c.newRequest(c.deletePropertyRequest(Window, Property), cookie)
+	return DeletePropertyCookie{cookie}
 }
 
 func (c *Conn) DeletePropertyChecked(Window Id, Property Id) DeletePropertyCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(deletePropertyRequest(Window, Property), cookie)
-	return DeletePropertyCookie(cookie)
+	c.newRequest(c.deletePropertyRequest(Window, Property), cookie)
+	return DeletePropertyCookie{cookie}
+}
+
+func (cook DeletePropertyCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for DeleteProperty
-func deletePropertyRequest(Window Id, Property Id) []byte {
+func (c *Conn) deletePropertyRequest(Window Id, Property Id) []byte {
 	size := 12
 	b := 0
 	buf := make([]byte, size)
@@ -7030,18 +7544,20 @@ func deletePropertyRequest(Window Id, Property Id) []byte {
 
 // Request GetProperty
 // size: 24
-type GetPropertyCookie cookie
+type GetPropertyCookie struct {
+	*cookie
+}
 
 func (c *Conn) GetProperty(Delete bool, Window Id, Property Id, Type Id, LongOffset uint32, LongLength uint32) GetPropertyCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(getPropertyRequest(Delete, Window, Property, Type, LongOffset, LongLength), cookie)
-	return GetPropertyCookie(cookie)
+	c.newRequest(c.getPropertyRequest(Delete, Window, Property, Type, LongOffset, LongLength), cookie)
+	return GetPropertyCookie{cookie}
 }
 
 func (c *Conn) GetPropertyUnchecked(Delete bool, Window Id, Property Id, Type Id, LongOffset uint32, LongLength uint32) GetPropertyCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(getPropertyRequest(Delete, Window, Property, Type, LongOffset, LongLength), cookie)
-	return GetPropertyCookie(cookie)
+	c.newRequest(c.getPropertyRequest(Delete, Window, Property, Type, LongOffset, LongLength), cookie)
+	return GetPropertyCookie{cookie}
 }
 
 // Request reply for GetProperty
@@ -7059,10 +7575,13 @@ type GetPropertyReply struct {
 
 // Waits and reads reply data from request GetProperty
 func (cook GetPropertyCookie) Reply() (*GetPropertyReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return getPropertyReply(buf), nil
 }
 
@@ -7098,8 +7617,12 @@ func getPropertyReply(buf []byte) *GetPropertyReply {
 	return v
 }
 
+func (cook GetPropertyCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for GetProperty
-func getPropertyRequest(Delete bool, Window Id, Property Id, Type Id, LongOffset uint32, LongLength uint32) []byte {
+func (c *Conn) getPropertyRequest(Delete bool, Window Id, Property Id, Type Id, LongOffset uint32, LongLength uint32) []byte {
 	size := 24
 	b := 0
 	buf := make([]byte, size)
@@ -7137,18 +7660,20 @@ func getPropertyRequest(Delete bool, Window Id, Property Id, Type Id, LongOffset
 
 // Request ListProperties
 // size: 8
-type ListPropertiesCookie cookie
+type ListPropertiesCookie struct {
+	*cookie
+}
 
 func (c *Conn) ListProperties(Window Id) ListPropertiesCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(listPropertiesRequest(Window), cookie)
-	return ListPropertiesCookie(cookie)
+	c.newRequest(c.listPropertiesRequest(Window), cookie)
+	return ListPropertiesCookie{cookie}
 }
 
 func (c *Conn) ListPropertiesUnchecked(Window Id) ListPropertiesCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(listPropertiesRequest(Window), cookie)
-	return ListPropertiesCookie(cookie)
+	c.newRequest(c.listPropertiesRequest(Window), cookie)
+	return ListPropertiesCookie{cookie}
 }
 
 // Request reply for ListProperties
@@ -7164,10 +7689,13 @@ type ListPropertiesReply struct {
 
 // Waits and reads reply data from request ListProperties
 func (cook ListPropertiesCookie) Reply() (*ListPropertiesReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return listPropertiesReply(buf), nil
 }
 
@@ -7199,8 +7727,12 @@ func listPropertiesReply(buf []byte) *ListPropertiesReply {
 	return v
 }
 
+func (cook ListPropertiesCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for ListProperties
-func listPropertiesRequest(Window Id) []byte {
+func (c *Conn) listPropertiesRequest(Window Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -7221,23 +7753,29 @@ func listPropertiesRequest(Window Id) []byte {
 
 // Request SetSelectionOwner
 // size: 16
-type SetSelectionOwnerCookie cookie
+type SetSelectionOwnerCookie struct {
+	*cookie
+}
 
 // Write request to wire for SetSelectionOwner
 func (c *Conn) SetSelectionOwner(Owner Id, Selection Id, Time Timestamp) SetSelectionOwnerCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(setSelectionOwnerRequest(Owner, Selection, Time), cookie)
-	return SetSelectionOwnerCookie(cookie)
+	c.newRequest(c.setSelectionOwnerRequest(Owner, Selection, Time), cookie)
+	return SetSelectionOwnerCookie{cookie}
 }
 
 func (c *Conn) SetSelectionOwnerChecked(Owner Id, Selection Id, Time Timestamp) SetSelectionOwnerCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(setSelectionOwnerRequest(Owner, Selection, Time), cookie)
-	return SetSelectionOwnerCookie(cookie)
+	c.newRequest(c.setSelectionOwnerRequest(Owner, Selection, Time), cookie)
+	return SetSelectionOwnerCookie{cookie}
+}
+
+func (cook SetSelectionOwnerCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for SetSelectionOwner
-func setSelectionOwnerRequest(Owner Id, Selection Id, Time Timestamp) []byte {
+func (c *Conn) setSelectionOwnerRequest(Owner Id, Selection Id, Time Timestamp) []byte {
 	size := 16
 	b := 0
 	buf := make([]byte, size)
@@ -7264,18 +7802,20 @@ func setSelectionOwnerRequest(Owner Id, Selection Id, Time Timestamp) []byte {
 
 // Request GetSelectionOwner
 // size: 8
-type GetSelectionOwnerCookie cookie
+type GetSelectionOwnerCookie struct {
+	*cookie
+}
 
 func (c *Conn) GetSelectionOwner(Selection Id) GetSelectionOwnerCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(getSelectionOwnerRequest(Selection), cookie)
-	return GetSelectionOwnerCookie(cookie)
+	c.newRequest(c.getSelectionOwnerRequest(Selection), cookie)
+	return GetSelectionOwnerCookie{cookie}
 }
 
 func (c *Conn) GetSelectionOwnerUnchecked(Selection Id) GetSelectionOwnerCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(getSelectionOwnerRequest(Selection), cookie)
-	return GetSelectionOwnerCookie(cookie)
+	c.newRequest(c.getSelectionOwnerRequest(Selection), cookie)
+	return GetSelectionOwnerCookie{cookie}
 }
 
 // Request reply for GetSelectionOwner
@@ -7289,10 +7829,13 @@ type GetSelectionOwnerReply struct {
 
 // Waits and reads reply data from request GetSelectionOwner
 func (cook GetSelectionOwnerCookie) Reply() (*GetSelectionOwnerReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return getSelectionOwnerReply(buf), nil
 }
 
@@ -7315,8 +7858,12 @@ func getSelectionOwnerReply(buf []byte) *GetSelectionOwnerReply {
 	return v
 }
 
+func (cook GetSelectionOwnerCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for GetSelectionOwner
-func getSelectionOwnerRequest(Selection Id) []byte {
+func (c *Conn) getSelectionOwnerRequest(Selection Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -7337,23 +7884,29 @@ func getSelectionOwnerRequest(Selection Id) []byte {
 
 // Request ConvertSelection
 // size: 24
-type ConvertSelectionCookie cookie
+type ConvertSelectionCookie struct {
+	*cookie
+}
 
 // Write request to wire for ConvertSelection
 func (c *Conn) ConvertSelection(Requestor Id, Selection Id, Target Id, Property Id, Time Timestamp) ConvertSelectionCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(convertSelectionRequest(Requestor, Selection, Target, Property, Time), cookie)
-	return ConvertSelectionCookie(cookie)
+	c.newRequest(c.convertSelectionRequest(Requestor, Selection, Target, Property, Time), cookie)
+	return ConvertSelectionCookie{cookie}
 }
 
 func (c *Conn) ConvertSelectionChecked(Requestor Id, Selection Id, Target Id, Property Id, Time Timestamp) ConvertSelectionCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(convertSelectionRequest(Requestor, Selection, Target, Property, Time), cookie)
-	return ConvertSelectionCookie(cookie)
+	c.newRequest(c.convertSelectionRequest(Requestor, Selection, Target, Property, Time), cookie)
+	return ConvertSelectionCookie{cookie}
+}
+
+func (cook ConvertSelectionCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for ConvertSelection
-func convertSelectionRequest(Requestor Id, Selection Id, Target Id, Property Id, Time Timestamp) []byte {
+func (c *Conn) convertSelectionRequest(Requestor Id, Selection Id, Target Id, Property Id, Time Timestamp) []byte {
 	size := 24
 	b := 0
 	buf := make([]byte, size)
@@ -7386,23 +7939,29 @@ func convertSelectionRequest(Requestor Id, Selection Id, Target Id, Property Id,
 
 // Request SendEvent
 // size: pad((12 + pad(32)))
-type SendEventCookie cookie
+type SendEventCookie struct {
+	*cookie
+}
 
 // Write request to wire for SendEvent
 func (c *Conn) SendEvent(Propagate bool, Destination Id, EventMask uint32, Event string) SendEventCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(sendEventRequest(Propagate, Destination, EventMask, Event), cookie)
-	return SendEventCookie(cookie)
+	c.newRequest(c.sendEventRequest(Propagate, Destination, EventMask, Event), cookie)
+	return SendEventCookie{cookie}
 }
 
 func (c *Conn) SendEventChecked(Propagate bool, Destination Id, EventMask uint32, Event string) SendEventCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(sendEventRequest(Propagate, Destination, EventMask, Event), cookie)
-	return SendEventCookie(cookie)
+	c.newRequest(c.sendEventRequest(Propagate, Destination, EventMask, Event), cookie)
+	return SendEventCookie{cookie}
+}
+
+func (cook SendEventCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for SendEvent
-func sendEventRequest(Propagate bool, Destination Id, EventMask uint32, Event string) []byte {
+func (c *Conn) sendEventRequest(Propagate bool, Destination Id, EventMask uint32, Event string) []byte {
 	size := pad((12 + pad(32)))
 	b := 0
 	buf := make([]byte, size)
@@ -7434,18 +7993,20 @@ func sendEventRequest(Propagate bool, Destination Id, EventMask uint32, Event st
 
 // Request GrabPointer
 // size: 24
-type GrabPointerCookie cookie
+type GrabPointerCookie struct {
+	*cookie
+}
 
 func (c *Conn) GrabPointer(OwnerEvents bool, GrabWindow Id, EventMask uint16, PointerMode byte, KeyboardMode byte, ConfineTo Id, Cursor Id, Time Timestamp) GrabPointerCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(grabPointerRequest(OwnerEvents, GrabWindow, EventMask, PointerMode, KeyboardMode, ConfineTo, Cursor, Time), cookie)
-	return GrabPointerCookie(cookie)
+	c.newRequest(c.grabPointerRequest(OwnerEvents, GrabWindow, EventMask, PointerMode, KeyboardMode, ConfineTo, Cursor, Time), cookie)
+	return GrabPointerCookie{cookie}
 }
 
 func (c *Conn) GrabPointerUnchecked(OwnerEvents bool, GrabWindow Id, EventMask uint16, PointerMode byte, KeyboardMode byte, ConfineTo Id, Cursor Id, Time Timestamp) GrabPointerCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(grabPointerRequest(OwnerEvents, GrabWindow, EventMask, PointerMode, KeyboardMode, ConfineTo, Cursor, Time), cookie)
-	return GrabPointerCookie(cookie)
+	c.newRequest(c.grabPointerRequest(OwnerEvents, GrabWindow, EventMask, PointerMode, KeyboardMode, ConfineTo, Cursor, Time), cookie)
+	return GrabPointerCookie{cookie}
 }
 
 // Request reply for GrabPointer
@@ -7458,10 +8019,13 @@ type GrabPointerReply struct {
 
 // Waits and reads reply data from request GrabPointer
 func (cook GrabPointerCookie) Reply() (*GrabPointerReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return grabPointerReply(buf), nil
 }
 
@@ -7473,11 +8037,21 @@ func grabPointerReply(buf []byte) *GrabPointerReply {
 	v.Status = buf[b]
 	b += 1
 
+	v.Sequence = Get16(buf[b:])
+	b += 2
+
+	v.Length = Get32(buf[b:]) // 4-byte units
+	b += 4
+
 	return v
 }
 
+func (cook GrabPointerCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for GrabPointer
-func grabPointerRequest(OwnerEvents bool, GrabWindow Id, EventMask uint16, PointerMode byte, KeyboardMode byte, ConfineTo Id, Cursor Id, Time Timestamp) []byte {
+func (c *Conn) grabPointerRequest(OwnerEvents bool, GrabWindow Id, EventMask uint16, PointerMode byte, KeyboardMode byte, ConfineTo Id, Cursor Id, Time Timestamp) []byte {
 	size := 24
 	b := 0
 	buf := make([]byte, size)
@@ -7521,23 +8095,29 @@ func grabPointerRequest(OwnerEvents bool, GrabWindow Id, EventMask uint16, Point
 
 // Request UngrabPointer
 // size: 8
-type UngrabPointerCookie cookie
+type UngrabPointerCookie struct {
+	*cookie
+}
 
 // Write request to wire for UngrabPointer
 func (c *Conn) UngrabPointer(Time Timestamp) UngrabPointerCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(ungrabPointerRequest(Time), cookie)
-	return UngrabPointerCookie(cookie)
+	c.newRequest(c.ungrabPointerRequest(Time), cookie)
+	return UngrabPointerCookie{cookie}
 }
 
 func (c *Conn) UngrabPointerChecked(Time Timestamp) UngrabPointerCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(ungrabPointerRequest(Time), cookie)
-	return UngrabPointerCookie(cookie)
+	c.newRequest(c.ungrabPointerRequest(Time), cookie)
+	return UngrabPointerCookie{cookie}
+}
+
+func (cook UngrabPointerCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for UngrabPointer
-func ungrabPointerRequest(Time Timestamp) []byte {
+func (c *Conn) ungrabPointerRequest(Time Timestamp) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -7558,23 +8138,29 @@ func ungrabPointerRequest(Time Timestamp) []byte {
 
 // Request GrabButton
 // size: 24
-type GrabButtonCookie cookie
+type GrabButtonCookie struct {
+	*cookie
+}
 
 // Write request to wire for GrabButton
 func (c *Conn) GrabButton(OwnerEvents bool, GrabWindow Id, EventMask uint16, PointerMode byte, KeyboardMode byte, ConfineTo Id, Cursor Id, Button byte, Modifiers uint16) GrabButtonCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(grabButtonRequest(OwnerEvents, GrabWindow, EventMask, PointerMode, KeyboardMode, ConfineTo, Cursor, Button, Modifiers), cookie)
-	return GrabButtonCookie(cookie)
+	c.newRequest(c.grabButtonRequest(OwnerEvents, GrabWindow, EventMask, PointerMode, KeyboardMode, ConfineTo, Cursor, Button, Modifiers), cookie)
+	return GrabButtonCookie{cookie}
 }
 
 func (c *Conn) GrabButtonChecked(OwnerEvents bool, GrabWindow Id, EventMask uint16, PointerMode byte, KeyboardMode byte, ConfineTo Id, Cursor Id, Button byte, Modifiers uint16) GrabButtonCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(grabButtonRequest(OwnerEvents, GrabWindow, EventMask, PointerMode, KeyboardMode, ConfineTo, Cursor, Button, Modifiers), cookie)
-	return GrabButtonCookie(cookie)
+	c.newRequest(c.grabButtonRequest(OwnerEvents, GrabWindow, EventMask, PointerMode, KeyboardMode, ConfineTo, Cursor, Button, Modifiers), cookie)
+	return GrabButtonCookie{cookie}
+}
+
+func (cook GrabButtonCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for GrabButton
-func grabButtonRequest(OwnerEvents bool, GrabWindow Id, EventMask uint16, PointerMode byte, KeyboardMode byte, ConfineTo Id, Cursor Id, Button byte, Modifiers uint16) []byte {
+func (c *Conn) grabButtonRequest(OwnerEvents bool, GrabWindow Id, EventMask uint16, PointerMode byte, KeyboardMode byte, ConfineTo Id, Cursor Id, Button byte, Modifiers uint16) []byte {
 	size := 24
 	b := 0
 	buf := make([]byte, size)
@@ -7623,23 +8209,29 @@ func grabButtonRequest(OwnerEvents bool, GrabWindow Id, EventMask uint16, Pointe
 
 // Request UngrabButton
 // size: 12
-type UngrabButtonCookie cookie
+type UngrabButtonCookie struct {
+	*cookie
+}
 
 // Write request to wire for UngrabButton
 func (c *Conn) UngrabButton(Button byte, GrabWindow Id, Modifiers uint16) UngrabButtonCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(ungrabButtonRequest(Button, GrabWindow, Modifiers), cookie)
-	return UngrabButtonCookie(cookie)
+	c.newRequest(c.ungrabButtonRequest(Button, GrabWindow, Modifiers), cookie)
+	return UngrabButtonCookie{cookie}
 }
 
 func (c *Conn) UngrabButtonChecked(Button byte, GrabWindow Id, Modifiers uint16) UngrabButtonCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(ungrabButtonRequest(Button, GrabWindow, Modifiers), cookie)
-	return UngrabButtonCookie(cookie)
+	c.newRequest(c.ungrabButtonRequest(Button, GrabWindow, Modifiers), cookie)
+	return UngrabButtonCookie{cookie}
+}
+
+func (cook UngrabButtonCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for UngrabButton
-func ungrabButtonRequest(Button byte, GrabWindow Id, Modifiers uint16) []byte {
+func (c *Conn) ungrabButtonRequest(Button byte, GrabWindow Id, Modifiers uint16) []byte {
 	size := 12
 	b := 0
 	buf := make([]byte, size)
@@ -7666,23 +8258,29 @@ func ungrabButtonRequest(Button byte, GrabWindow Id, Modifiers uint16) []byte {
 
 // Request ChangeActivePointerGrab
 // size: 16
-type ChangeActivePointerGrabCookie cookie
+type ChangeActivePointerGrabCookie struct {
+	*cookie
+}
 
 // Write request to wire for ChangeActivePointerGrab
 func (c *Conn) ChangeActivePointerGrab(Cursor Id, Time Timestamp, EventMask uint16) ChangeActivePointerGrabCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(changeActivePointerGrabRequest(Cursor, Time, EventMask), cookie)
-	return ChangeActivePointerGrabCookie(cookie)
+	c.newRequest(c.changeActivePointerGrabRequest(Cursor, Time, EventMask), cookie)
+	return ChangeActivePointerGrabCookie{cookie}
 }
 
 func (c *Conn) ChangeActivePointerGrabChecked(Cursor Id, Time Timestamp, EventMask uint16) ChangeActivePointerGrabCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(changeActivePointerGrabRequest(Cursor, Time, EventMask), cookie)
-	return ChangeActivePointerGrabCookie(cookie)
+	c.newRequest(c.changeActivePointerGrabRequest(Cursor, Time, EventMask), cookie)
+	return ChangeActivePointerGrabCookie{cookie}
+}
+
+func (cook ChangeActivePointerGrabCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for ChangeActivePointerGrab
-func changeActivePointerGrabRequest(Cursor Id, Time Timestamp, EventMask uint16) []byte {
+func (c *Conn) changeActivePointerGrabRequest(Cursor Id, Time Timestamp, EventMask uint16) []byte {
 	size := 16
 	b := 0
 	buf := make([]byte, size)
@@ -7711,18 +8309,20 @@ func changeActivePointerGrabRequest(Cursor Id, Time Timestamp, EventMask uint16)
 
 // Request GrabKeyboard
 // size: 16
-type GrabKeyboardCookie cookie
+type GrabKeyboardCookie struct {
+	*cookie
+}
 
 func (c *Conn) GrabKeyboard(OwnerEvents bool, GrabWindow Id, Time Timestamp, PointerMode byte, KeyboardMode byte) GrabKeyboardCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(grabKeyboardRequest(OwnerEvents, GrabWindow, Time, PointerMode, KeyboardMode), cookie)
-	return GrabKeyboardCookie(cookie)
+	c.newRequest(c.grabKeyboardRequest(OwnerEvents, GrabWindow, Time, PointerMode, KeyboardMode), cookie)
+	return GrabKeyboardCookie{cookie}
 }
 
 func (c *Conn) GrabKeyboardUnchecked(OwnerEvents bool, GrabWindow Id, Time Timestamp, PointerMode byte, KeyboardMode byte) GrabKeyboardCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(grabKeyboardRequest(OwnerEvents, GrabWindow, Time, PointerMode, KeyboardMode), cookie)
-	return GrabKeyboardCookie(cookie)
+	c.newRequest(c.grabKeyboardRequest(OwnerEvents, GrabWindow, Time, PointerMode, KeyboardMode), cookie)
+	return GrabKeyboardCookie{cookie}
 }
 
 // Request reply for GrabKeyboard
@@ -7735,10 +8335,13 @@ type GrabKeyboardReply struct {
 
 // Waits and reads reply data from request GrabKeyboard
 func (cook GrabKeyboardCookie) Reply() (*GrabKeyboardReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return grabKeyboardReply(buf), nil
 }
 
@@ -7750,11 +8353,21 @@ func grabKeyboardReply(buf []byte) *GrabKeyboardReply {
 	v.Status = buf[b]
 	b += 1
 
+	v.Sequence = Get16(buf[b:])
+	b += 2
+
+	v.Length = Get32(buf[b:]) // 4-byte units
+	b += 4
+
 	return v
 }
 
+func (cook GrabKeyboardCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for GrabKeyboard
-func grabKeyboardRequest(OwnerEvents bool, GrabWindow Id, Time Timestamp, PointerMode byte, KeyboardMode byte) []byte {
+func (c *Conn) grabKeyboardRequest(OwnerEvents bool, GrabWindow Id, Time Timestamp, PointerMode byte, KeyboardMode byte) []byte {
 	size := 16
 	b := 0
 	buf := make([]byte, size)
@@ -7791,23 +8404,29 @@ func grabKeyboardRequest(OwnerEvents bool, GrabWindow Id, Time Timestamp, Pointe
 
 // Request UngrabKeyboard
 // size: 8
-type UngrabKeyboardCookie cookie
+type UngrabKeyboardCookie struct {
+	*cookie
+}
 
 // Write request to wire for UngrabKeyboard
 func (c *Conn) UngrabKeyboard(Time Timestamp) UngrabKeyboardCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(ungrabKeyboardRequest(Time), cookie)
-	return UngrabKeyboardCookie(cookie)
+	c.newRequest(c.ungrabKeyboardRequest(Time), cookie)
+	return UngrabKeyboardCookie{cookie}
 }
 
 func (c *Conn) UngrabKeyboardChecked(Time Timestamp) UngrabKeyboardCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(ungrabKeyboardRequest(Time), cookie)
-	return UngrabKeyboardCookie(cookie)
+	c.newRequest(c.ungrabKeyboardRequest(Time), cookie)
+	return UngrabKeyboardCookie{cookie}
+}
+
+func (cook UngrabKeyboardCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for UngrabKeyboard
-func ungrabKeyboardRequest(Time Timestamp) []byte {
+func (c *Conn) ungrabKeyboardRequest(Time Timestamp) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -7828,23 +8447,29 @@ func ungrabKeyboardRequest(Time Timestamp) []byte {
 
 // Request GrabKey
 // size: 16
-type GrabKeyCookie cookie
+type GrabKeyCookie struct {
+	*cookie
+}
 
 // Write request to wire for GrabKey
 func (c *Conn) GrabKey(OwnerEvents bool, GrabWindow Id, Modifiers uint16, Key Keycode, PointerMode byte, KeyboardMode byte) GrabKeyCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(grabKeyRequest(OwnerEvents, GrabWindow, Modifiers, Key, PointerMode, KeyboardMode), cookie)
-	return GrabKeyCookie(cookie)
+	c.newRequest(c.grabKeyRequest(OwnerEvents, GrabWindow, Modifiers, Key, PointerMode, KeyboardMode), cookie)
+	return GrabKeyCookie{cookie}
 }
 
 func (c *Conn) GrabKeyChecked(OwnerEvents bool, GrabWindow Id, Modifiers uint16, Key Keycode, PointerMode byte, KeyboardMode byte) GrabKeyCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(grabKeyRequest(OwnerEvents, GrabWindow, Modifiers, Key, PointerMode, KeyboardMode), cookie)
-	return GrabKeyCookie(cookie)
+	c.newRequest(c.grabKeyRequest(OwnerEvents, GrabWindow, Modifiers, Key, PointerMode, KeyboardMode), cookie)
+	return GrabKeyCookie{cookie}
+}
+
+func (cook GrabKeyCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for GrabKey
-func grabKeyRequest(OwnerEvents bool, GrabWindow Id, Modifiers uint16, Key Keycode, PointerMode byte, KeyboardMode byte) []byte {
+func (c *Conn) grabKeyRequest(OwnerEvents bool, GrabWindow Id, Modifiers uint16, Key Keycode, PointerMode byte, KeyboardMode byte) []byte {
 	size := 16
 	b := 0
 	buf := make([]byte, size)
@@ -7884,23 +8509,29 @@ func grabKeyRequest(OwnerEvents bool, GrabWindow Id, Modifiers uint16, Key Keyco
 
 // Request UngrabKey
 // size: 12
-type UngrabKeyCookie cookie
+type UngrabKeyCookie struct {
+	*cookie
+}
 
 // Write request to wire for UngrabKey
 func (c *Conn) UngrabKey(Key Keycode, GrabWindow Id, Modifiers uint16) UngrabKeyCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(ungrabKeyRequest(Key, GrabWindow, Modifiers), cookie)
-	return UngrabKeyCookie(cookie)
+	c.newRequest(c.ungrabKeyRequest(Key, GrabWindow, Modifiers), cookie)
+	return UngrabKeyCookie{cookie}
 }
 
 func (c *Conn) UngrabKeyChecked(Key Keycode, GrabWindow Id, Modifiers uint16) UngrabKeyCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(ungrabKeyRequest(Key, GrabWindow, Modifiers), cookie)
-	return UngrabKeyCookie(cookie)
+	c.newRequest(c.ungrabKeyRequest(Key, GrabWindow, Modifiers), cookie)
+	return UngrabKeyCookie{cookie}
+}
+
+func (cook UngrabKeyCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for UngrabKey
-func ungrabKeyRequest(Key Keycode, GrabWindow Id, Modifiers uint16) []byte {
+func (c *Conn) ungrabKeyRequest(Key Keycode, GrabWindow Id, Modifiers uint16) []byte {
 	size := 12
 	b := 0
 	buf := make([]byte, size)
@@ -7927,23 +8558,29 @@ func ungrabKeyRequest(Key Keycode, GrabWindow Id, Modifiers uint16) []byte {
 
 // Request AllowEvents
 // size: 8
-type AllowEventsCookie cookie
+type AllowEventsCookie struct {
+	*cookie
+}
 
 // Write request to wire for AllowEvents
 func (c *Conn) AllowEvents(Mode byte, Time Timestamp) AllowEventsCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(allowEventsRequest(Mode, Time), cookie)
-	return AllowEventsCookie(cookie)
+	c.newRequest(c.allowEventsRequest(Mode, Time), cookie)
+	return AllowEventsCookie{cookie}
 }
 
 func (c *Conn) AllowEventsChecked(Mode byte, Time Timestamp) AllowEventsCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(allowEventsRequest(Mode, Time), cookie)
-	return AllowEventsCookie(cookie)
+	c.newRequest(c.allowEventsRequest(Mode, Time), cookie)
+	return AllowEventsCookie{cookie}
+}
+
+func (cook AllowEventsCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for AllowEvents
-func allowEventsRequest(Mode byte, Time Timestamp) []byte {
+func (c *Conn) allowEventsRequest(Mode byte, Time Timestamp) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -7965,23 +8602,29 @@ func allowEventsRequest(Mode byte, Time Timestamp) []byte {
 
 // Request GrabServer
 // size: 4
-type GrabServerCookie cookie
+type GrabServerCookie struct {
+	*cookie
+}
 
 // Write request to wire for GrabServer
 func (c *Conn) GrabServer() GrabServerCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(grabServerRequest(), cookie)
-	return GrabServerCookie(cookie)
+	c.newRequest(c.grabServerRequest(), cookie)
+	return GrabServerCookie{cookie}
 }
 
 func (c *Conn) GrabServerChecked() GrabServerCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(grabServerRequest(), cookie)
-	return GrabServerCookie(cookie)
+	c.newRequest(c.grabServerRequest(), cookie)
+	return GrabServerCookie{cookie}
+}
+
+func (cook GrabServerCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for GrabServer
-func grabServerRequest() []byte {
+func (c *Conn) grabServerRequest() []byte {
 	size := 4
 	b := 0
 	buf := make([]byte, size)
@@ -7989,28 +8632,38 @@ func grabServerRequest() []byte {
 	buf[b] = 36 // request opcode
 	b += 1
 
+	b += 1                         // padding
+	Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
+	b += 2
+
 	return buf
 }
 
 // Request UngrabServer
 // size: 4
-type UngrabServerCookie cookie
+type UngrabServerCookie struct {
+	*cookie
+}
 
 // Write request to wire for UngrabServer
 func (c *Conn) UngrabServer() UngrabServerCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(ungrabServerRequest(), cookie)
-	return UngrabServerCookie(cookie)
+	c.newRequest(c.ungrabServerRequest(), cookie)
+	return UngrabServerCookie{cookie}
 }
 
 func (c *Conn) UngrabServerChecked() UngrabServerCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(ungrabServerRequest(), cookie)
-	return UngrabServerCookie(cookie)
+	c.newRequest(c.ungrabServerRequest(), cookie)
+	return UngrabServerCookie{cookie}
+}
+
+func (cook UngrabServerCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for UngrabServer
-func ungrabServerRequest() []byte {
+func (c *Conn) ungrabServerRequest() []byte {
 	size := 4
 	b := 0
 	buf := make([]byte, size)
@@ -8018,23 +8671,29 @@ func ungrabServerRequest() []byte {
 	buf[b] = 37 // request opcode
 	b += 1
 
+	b += 1                         // padding
+	Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
+	b += 2
+
 	return buf
 }
 
 // Request QueryPointer
 // size: 8
-type QueryPointerCookie cookie
+type QueryPointerCookie struct {
+	*cookie
+}
 
 func (c *Conn) QueryPointer(Window Id) QueryPointerCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(queryPointerRequest(Window), cookie)
-	return QueryPointerCookie(cookie)
+	c.newRequest(c.queryPointerRequest(Window), cookie)
+	return QueryPointerCookie{cookie}
 }
 
 func (c *Conn) QueryPointerUnchecked(Window Id) QueryPointerCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(queryPointerRequest(Window), cookie)
-	return QueryPointerCookie(cookie)
+	c.newRequest(c.queryPointerRequest(Window), cookie)
+	return QueryPointerCookie{cookie}
 }
 
 // Request reply for QueryPointer
@@ -8055,10 +8714,13 @@ type QueryPointerReply struct {
 
 // Waits and reads reply data from request QueryPointer
 func (cook QueryPointerCookie) Reply() (*QueryPointerReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return queryPointerReply(buf), nil
 }
 
@@ -8106,8 +8768,12 @@ func queryPointerReply(buf []byte) *QueryPointerReply {
 	return v
 }
 
+func (cook QueryPointerCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for QueryPointer
-func queryPointerRequest(Window Id) []byte {
+func (c *Conn) queryPointerRequest(Window Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -8128,18 +8794,20 @@ func queryPointerRequest(Window Id) []byte {
 
 // Request GetMotionEvents
 // size: 16
-type GetMotionEventsCookie cookie
+type GetMotionEventsCookie struct {
+	*cookie
+}
 
 func (c *Conn) GetMotionEvents(Window Id, Start Timestamp, Stop Timestamp) GetMotionEventsCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(getMotionEventsRequest(Window, Start, Stop), cookie)
-	return GetMotionEventsCookie(cookie)
+	c.newRequest(c.getMotionEventsRequest(Window, Start, Stop), cookie)
+	return GetMotionEventsCookie{cookie}
 }
 
 func (c *Conn) GetMotionEventsUnchecked(Window Id, Start Timestamp, Stop Timestamp) GetMotionEventsCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(getMotionEventsRequest(Window, Start, Stop), cookie)
-	return GetMotionEventsCookie(cookie)
+	c.newRequest(c.getMotionEventsRequest(Window, Start, Stop), cookie)
+	return GetMotionEventsCookie{cookie}
 }
 
 // Request reply for GetMotionEvents
@@ -8155,10 +8823,13 @@ type GetMotionEventsReply struct {
 
 // Waits and reads reply data from request GetMotionEvents
 func (cook GetMotionEventsCookie) Reply() (*GetMotionEventsReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return getMotionEventsReply(buf), nil
 }
 
@@ -8186,8 +8857,12 @@ func getMotionEventsReply(buf []byte) *GetMotionEventsReply {
 	return v
 }
 
+func (cook GetMotionEventsCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for GetMotionEvents
-func getMotionEventsRequest(Window Id, Start Timestamp, Stop Timestamp) []byte {
+func (c *Conn) getMotionEventsRequest(Window Id, Start Timestamp, Stop Timestamp) []byte {
 	size := 16
 	b := 0
 	buf := make([]byte, size)
@@ -8214,18 +8889,20 @@ func getMotionEventsRequest(Window Id, Start Timestamp, Stop Timestamp) []byte {
 
 // Request TranslateCoordinates
 // size: 16
-type TranslateCoordinatesCookie cookie
+type TranslateCoordinatesCookie struct {
+	*cookie
+}
 
 func (c *Conn) TranslateCoordinates(SrcWindow Id, DstWindow Id, SrcX int16, SrcY int16) TranslateCoordinatesCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(translateCoordinatesRequest(SrcWindow, DstWindow, SrcX, SrcY), cookie)
-	return TranslateCoordinatesCookie(cookie)
+	c.newRequest(c.translateCoordinatesRequest(SrcWindow, DstWindow, SrcX, SrcY), cookie)
+	return TranslateCoordinatesCookie{cookie}
 }
 
 func (c *Conn) TranslateCoordinatesUnchecked(SrcWindow Id, DstWindow Id, SrcX int16, SrcY int16) TranslateCoordinatesCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(translateCoordinatesRequest(SrcWindow, DstWindow, SrcX, SrcY), cookie)
-	return TranslateCoordinatesCookie(cookie)
+	c.newRequest(c.translateCoordinatesRequest(SrcWindow, DstWindow, SrcX, SrcY), cookie)
+	return TranslateCoordinatesCookie{cookie}
 }
 
 // Request reply for TranslateCoordinates
@@ -8241,10 +8918,13 @@ type TranslateCoordinatesReply struct {
 
 // Waits and reads reply data from request TranslateCoordinates
 func (cook TranslateCoordinatesCookie) Reply() (*TranslateCoordinatesReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return translateCoordinatesReply(buf), nil
 }
 
@@ -8278,8 +8958,12 @@ func translateCoordinatesReply(buf []byte) *TranslateCoordinatesReply {
 	return v
 }
 
+func (cook TranslateCoordinatesCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for TranslateCoordinates
-func translateCoordinatesRequest(SrcWindow Id, DstWindow Id, SrcX int16, SrcY int16) []byte {
+func (c *Conn) translateCoordinatesRequest(SrcWindow Id, DstWindow Id, SrcX int16, SrcY int16) []byte {
 	size := 16
 	b := 0
 	buf := make([]byte, size)
@@ -8309,23 +8993,29 @@ func translateCoordinatesRequest(SrcWindow Id, DstWindow Id, SrcX int16, SrcY in
 
 // Request WarpPointer
 // size: 24
-type WarpPointerCookie cookie
+type WarpPointerCookie struct {
+	*cookie
+}
 
 // Write request to wire for WarpPointer
 func (c *Conn) WarpPointer(SrcWindow Id, DstWindow Id, SrcX int16, SrcY int16, SrcWidth uint16, SrcHeight uint16, DstX int16, DstY int16) WarpPointerCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(warpPointerRequest(SrcWindow, DstWindow, SrcX, SrcY, SrcWidth, SrcHeight, DstX, DstY), cookie)
-	return WarpPointerCookie(cookie)
+	c.newRequest(c.warpPointerRequest(SrcWindow, DstWindow, SrcX, SrcY, SrcWidth, SrcHeight, DstX, DstY), cookie)
+	return WarpPointerCookie{cookie}
 }
 
 func (c *Conn) WarpPointerChecked(SrcWindow Id, DstWindow Id, SrcX int16, SrcY int16, SrcWidth uint16, SrcHeight uint16, DstX int16, DstY int16) WarpPointerCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(warpPointerRequest(SrcWindow, DstWindow, SrcX, SrcY, SrcWidth, SrcHeight, DstX, DstY), cookie)
-	return WarpPointerCookie(cookie)
+	c.newRequest(c.warpPointerRequest(SrcWindow, DstWindow, SrcX, SrcY, SrcWidth, SrcHeight, DstX, DstY), cookie)
+	return WarpPointerCookie{cookie}
+}
+
+func (cook WarpPointerCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for WarpPointer
-func warpPointerRequest(SrcWindow Id, DstWindow Id, SrcX int16, SrcY int16, SrcWidth uint16, SrcHeight uint16, DstX int16, DstY int16) []byte {
+func (c *Conn) warpPointerRequest(SrcWindow Id, DstWindow Id, SrcX int16, SrcY int16, SrcWidth uint16, SrcHeight uint16, DstX int16, DstY int16) []byte {
 	size := 24
 	b := 0
 	buf := make([]byte, size)
@@ -8367,23 +9057,29 @@ func warpPointerRequest(SrcWindow Id, DstWindow Id, SrcX int16, SrcY int16, SrcW
 
 // Request SetInputFocus
 // size: 12
-type SetInputFocusCookie cookie
+type SetInputFocusCookie struct {
+	*cookie
+}
 
 // Write request to wire for SetInputFocus
 func (c *Conn) SetInputFocus(RevertTo byte, Focus Id, Time Timestamp) SetInputFocusCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(setInputFocusRequest(RevertTo, Focus, Time), cookie)
-	return SetInputFocusCookie(cookie)
+	c.newRequest(c.setInputFocusRequest(RevertTo, Focus, Time), cookie)
+	return SetInputFocusCookie{cookie}
 }
 
 func (c *Conn) SetInputFocusChecked(RevertTo byte, Focus Id, Time Timestamp) SetInputFocusCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(setInputFocusRequest(RevertTo, Focus, Time), cookie)
-	return SetInputFocusCookie(cookie)
+	c.newRequest(c.setInputFocusRequest(RevertTo, Focus, Time), cookie)
+	return SetInputFocusCookie{cookie}
+}
+
+func (cook SetInputFocusCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for SetInputFocus
-func setInputFocusRequest(RevertTo byte, Focus Id, Time Timestamp) []byte {
+func (c *Conn) setInputFocusRequest(RevertTo byte, Focus Id, Time Timestamp) []byte {
 	size := 12
 	b := 0
 	buf := make([]byte, size)
@@ -8408,18 +9104,20 @@ func setInputFocusRequest(RevertTo byte, Focus Id, Time Timestamp) []byte {
 
 // Request GetInputFocus
 // size: 4
-type GetInputFocusCookie cookie
+type GetInputFocusCookie struct {
+	*cookie
+}
 
 func (c *Conn) GetInputFocus() GetInputFocusCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(getInputFocusRequest(), cookie)
-	return GetInputFocusCookie(cookie)
+	c.newRequest(c.getInputFocusRequest(), cookie)
+	return GetInputFocusCookie{cookie}
 }
 
 func (c *Conn) GetInputFocusUnchecked() GetInputFocusCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(getInputFocusRequest(), cookie)
-	return GetInputFocusCookie(cookie)
+	c.newRequest(c.getInputFocusRequest(), cookie)
+	return GetInputFocusCookie{cookie}
 }
 
 // Request reply for GetInputFocus
@@ -8433,10 +9131,13 @@ type GetInputFocusReply struct {
 
 // Waits and reads reply data from request GetInputFocus
 func (cook GetInputFocusCookie) Reply() (*GetInputFocusReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return getInputFocusReply(buf), nil
 }
 
@@ -8460,8 +9161,12 @@ func getInputFocusReply(buf []byte) *GetInputFocusReply {
 	return v
 }
 
+func (cook GetInputFocusCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for GetInputFocus
-func getInputFocusRequest() []byte {
+func (c *Conn) getInputFocusRequest() []byte {
 	size := 4
 	b := 0
 	buf := make([]byte, size)
@@ -8469,23 +9174,29 @@ func getInputFocusRequest() []byte {
 	buf[b] = 43 // request opcode
 	b += 1
 
+	b += 1                         // padding
+	Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
+	b += 2
+
 	return buf
 }
 
 // Request QueryKeymap
 // size: 4
-type QueryKeymapCookie cookie
+type QueryKeymapCookie struct {
+	*cookie
+}
 
 func (c *Conn) QueryKeymap() QueryKeymapCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(queryKeymapRequest(), cookie)
-	return QueryKeymapCookie(cookie)
+	c.newRequest(c.queryKeymapRequest(), cookie)
+	return QueryKeymapCookie{cookie}
 }
 
 func (c *Conn) QueryKeymapUnchecked() QueryKeymapCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(queryKeymapRequest(), cookie)
-	return QueryKeymapCookie(cookie)
+	c.newRequest(c.queryKeymapRequest(), cookie)
+	return QueryKeymapCookie{cookie}
 }
 
 // Request reply for QueryKeymap
@@ -8499,10 +9210,13 @@ type QueryKeymapReply struct {
 
 // Waits and reads reply data from request QueryKeymap
 func (cook QueryKeymapCookie) Reply() (*QueryKeymapReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return queryKeymapReply(buf), nil
 }
 
@@ -8526,8 +9240,12 @@ func queryKeymapReply(buf []byte) *QueryKeymapReply {
 	return v
 }
 
+func (cook QueryKeymapCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for QueryKeymap
-func queryKeymapRequest() []byte {
+func (c *Conn) queryKeymapRequest() []byte {
 	size := 4
 	b := 0
 	buf := make([]byte, size)
@@ -8535,28 +9253,38 @@ func queryKeymapRequest() []byte {
 	buf[b] = 44 // request opcode
 	b += 1
 
+	b += 1                         // padding
+	Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
+	b += 2
+
 	return buf
 }
 
 // Request OpenFont
 // size: pad((12 + pad((int(NameLen) * 1))))
-type OpenFontCookie cookie
+type OpenFontCookie struct {
+	*cookie
+}
 
 // Write request to wire for OpenFont
 func (c *Conn) OpenFont(Fid Id, NameLen uint16, Name string) OpenFontCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(openFontRequest(Fid, NameLen, Name), cookie)
-	return OpenFontCookie(cookie)
+	c.newRequest(c.openFontRequest(Fid, NameLen, Name), cookie)
+	return OpenFontCookie{cookie}
 }
 
 func (c *Conn) OpenFontChecked(Fid Id, NameLen uint16, Name string) OpenFontCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(openFontRequest(Fid, NameLen, Name), cookie)
-	return OpenFontCookie(cookie)
+	c.newRequest(c.openFontRequest(Fid, NameLen, Name), cookie)
+	return OpenFontCookie{cookie}
+}
+
+func (cook OpenFontCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for OpenFont
-func openFontRequest(Fid Id, NameLen uint16, Name string) []byte {
+func (c *Conn) openFontRequest(Fid Id, NameLen uint16, Name string) []byte {
 	size := pad((12 + pad((int(NameLen) * 1))))
 	b := 0
 	buf := make([]byte, size)
@@ -8585,23 +9313,29 @@ func openFontRequest(Fid Id, NameLen uint16, Name string) []byte {
 
 // Request CloseFont
 // size: 8
-type CloseFontCookie cookie
+type CloseFontCookie struct {
+	*cookie
+}
 
 // Write request to wire for CloseFont
 func (c *Conn) CloseFont(Font Id) CloseFontCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(closeFontRequest(Font), cookie)
-	return CloseFontCookie(cookie)
+	c.newRequest(c.closeFontRequest(Font), cookie)
+	return CloseFontCookie{cookie}
 }
 
 func (c *Conn) CloseFontChecked(Font Id) CloseFontCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(closeFontRequest(Font), cookie)
-	return CloseFontCookie(cookie)
+	c.newRequest(c.closeFontRequest(Font), cookie)
+	return CloseFontCookie{cookie}
+}
+
+func (cook CloseFontCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for CloseFont
-func closeFontRequest(Font Id) []byte {
+func (c *Conn) closeFontRequest(Font Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -8622,18 +9356,20 @@ func closeFontRequest(Font Id) []byte {
 
 // Request QueryFont
 // size: 8
-type QueryFontCookie cookie
+type QueryFontCookie struct {
+	*cookie
+}
 
 func (c *Conn) QueryFont(Font Id) QueryFontCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(queryFontRequest(Font), cookie)
-	return QueryFontCookie(cookie)
+	c.newRequest(c.queryFontRequest(Font), cookie)
+	return QueryFontCookie{cookie}
 }
 
 func (c *Conn) QueryFontUnchecked(Font Id) QueryFontCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(queryFontRequest(Font), cookie)
-	return QueryFontCookie(cookie)
+	c.newRequest(c.queryFontRequest(Font), cookie)
+	return QueryFontCookie{cookie}
 }
 
 // Request reply for QueryFont
@@ -8663,10 +9399,13 @@ type QueryFontReply struct {
 
 // Waits and reads reply data from request QueryFont
 func (cook QueryFontCookie) Reply() (*QueryFontReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return queryFontReply(buf), nil
 }
 
@@ -8739,8 +9478,12 @@ func queryFontReply(buf []byte) *QueryFontReply {
 	return v
 }
 
+func (cook QueryFontCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for QueryFont
-func queryFontRequest(Font Id) []byte {
+func (c *Conn) queryFontRequest(Font Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -8761,18 +9504,20 @@ func queryFontRequest(Font Id) []byte {
 
 // Request QueryTextExtents
 // size: pad((8 + pad((len(String) * 2))))
-type QueryTextExtentsCookie cookie
+type QueryTextExtentsCookie struct {
+	*cookie
+}
 
 func (c *Conn) QueryTextExtents(Font Id, String []Char2b, StringLen uint16) QueryTextExtentsCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(queryTextExtentsRequest(Font, String, StringLen), cookie)
-	return QueryTextExtentsCookie(cookie)
+	c.newRequest(c.queryTextExtentsRequest(Font, String, StringLen), cookie)
+	return QueryTextExtentsCookie{cookie}
 }
 
 func (c *Conn) QueryTextExtentsUnchecked(Font Id, String []Char2b, StringLen uint16) QueryTextExtentsCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(queryTextExtentsRequest(Font, String, StringLen), cookie)
-	return QueryTextExtentsCookie(cookie)
+	c.newRequest(c.queryTextExtentsRequest(Font, String, StringLen), cookie)
+	return QueryTextExtentsCookie{cookie}
 }
 
 // Request reply for QueryTextExtents
@@ -8792,10 +9537,13 @@ type QueryTextExtentsReply struct {
 
 // Waits and reads reply data from request QueryTextExtents
 func (cook QueryTextExtentsCookie) Reply() (*QueryTextExtentsReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return queryTextExtentsReply(buf), nil
 }
 
@@ -8837,8 +9585,12 @@ func queryTextExtentsReply(buf []byte) *QueryTextExtentsReply {
 	return v
 }
 
+func (cook QueryTextExtentsCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for QueryTextExtents
-func queryTextExtentsRequest(Font Id, String []Char2b, StringLen uint16) []byte {
+func (c *Conn) queryTextExtentsRequest(Font Id, String []Char2b, StringLen uint16) []byte {
 	size := pad((8 + pad((len(String) * 2))))
 	b := 0
 	buf := make([]byte, size)
@@ -8864,18 +9616,20 @@ func queryTextExtentsRequest(Font Id, String []Char2b, StringLen uint16) []byte
 
 // Request ListFonts
 // size: pad((8 + pad((int(PatternLen) * 1))))
-type ListFontsCookie cookie
+type ListFontsCookie struct {
+	*cookie
+}
 
 func (c *Conn) ListFonts(MaxNames uint16, PatternLen uint16, Pattern string) ListFontsCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(listFontsRequest(MaxNames, PatternLen, Pattern), cookie)
-	return ListFontsCookie(cookie)
+	c.newRequest(c.listFontsRequest(MaxNames, PatternLen, Pattern), cookie)
+	return ListFontsCookie{cookie}
 }
 
 func (c *Conn) ListFontsUnchecked(MaxNames uint16, PatternLen uint16, Pattern string) ListFontsCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(listFontsRequest(MaxNames, PatternLen, Pattern), cookie)
-	return ListFontsCookie(cookie)
+	c.newRequest(c.listFontsRequest(MaxNames, PatternLen, Pattern), cookie)
+	return ListFontsCookie{cookie}
 }
 
 // Request reply for ListFonts
@@ -8891,10 +9645,13 @@ type ListFontsReply struct {
 
 // Waits and reads reply data from request ListFonts
 func (cook ListFontsCookie) Reply() (*ListFontsReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return listFontsReply(buf), nil
 }
 
@@ -8922,8 +9679,12 @@ func listFontsReply(buf []byte) *ListFontsReply {
 	return v
 }
 
+func (cook ListFontsCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for ListFonts
-func listFontsRequest(MaxNames uint16, PatternLen uint16, Pattern string) []byte {
+func (c *Conn) listFontsRequest(MaxNames uint16, PatternLen uint16, Pattern string) []byte {
 	size := pad((8 + pad((int(PatternLen) * 1))))
 	b := 0
 	buf := make([]byte, size)
@@ -8950,18 +9711,20 @@ func listFontsRequest(MaxNames uint16, PatternLen uint16, Pattern string) []byte
 
 // Request ListFontsWithInfo
 // size: pad((8 + pad((int(PatternLen) * 1))))
-type ListFontsWithInfoCookie cookie
+type ListFontsWithInfoCookie struct {
+	*cookie
+}
 
 func (c *Conn) ListFontsWithInfo(MaxNames uint16, PatternLen uint16, Pattern string) ListFontsWithInfoCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(listFontsWithInfoRequest(MaxNames, PatternLen, Pattern), cookie)
-	return ListFontsWithInfoCookie(cookie)
+	c.newRequest(c.listFontsWithInfoRequest(MaxNames, PatternLen, Pattern), cookie)
+	return ListFontsWithInfoCookie{cookie}
 }
 
 func (c *Conn) ListFontsWithInfoUnchecked(MaxNames uint16, PatternLen uint16, Pattern string) ListFontsWithInfoCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(listFontsWithInfoRequest(MaxNames, PatternLen, Pattern), cookie)
-	return ListFontsWithInfoCookie(cookie)
+	c.newRequest(c.listFontsWithInfoRequest(MaxNames, PatternLen, Pattern), cookie)
+	return ListFontsWithInfoCookie{cookie}
 }
 
 // Request reply for ListFontsWithInfo
@@ -8991,10 +9754,13 @@ type ListFontsWithInfoReply struct {
 
 // Waits and reads reply data from request ListFontsWithInfo
 func (cook ListFontsWithInfoCookie) Reply() (*ListFontsWithInfoReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return listFontsWithInfoReply(buf), nil
 }
 
@@ -9072,8 +9838,12 @@ func listFontsWithInfoReply(buf []byte) *ListFontsWithInfoReply {
 	return v
 }
 
+func (cook ListFontsWithInfoCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for ListFontsWithInfo
-func listFontsWithInfoRequest(MaxNames uint16, PatternLen uint16, Pattern string) []byte {
+func (c *Conn) listFontsWithInfoRequest(MaxNames uint16, PatternLen uint16, Pattern string) []byte {
 	size := pad((8 + pad((int(PatternLen) * 1))))
 	b := 0
 	buf := make([]byte, size)
@@ -9100,23 +9870,29 @@ func listFontsWithInfoRequest(MaxNames uint16, PatternLen uint16, Pattern string
 
 // Request SetFontPath
 // size: pad((8 + StrListSize(Font)))
-type SetFontPathCookie cookie
+type SetFontPathCookie struct {
+	*cookie
+}
 
 // Write request to wire for SetFontPath
 func (c *Conn) SetFontPath(FontQty uint16, Font []Str) SetFontPathCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(setFontPathRequest(FontQty, Font), cookie)
-	return SetFontPathCookie(cookie)
+	c.newRequest(c.setFontPathRequest(FontQty, Font), cookie)
+	return SetFontPathCookie{cookie}
 }
 
 func (c *Conn) SetFontPathChecked(FontQty uint16, Font []Str) SetFontPathCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(setFontPathRequest(FontQty, Font), cookie)
-	return SetFontPathCookie(cookie)
+	c.newRequest(c.setFontPathRequest(FontQty, Font), cookie)
+	return SetFontPathCookie{cookie}
+}
+
+func (cook SetFontPathCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for SetFontPath
-func setFontPathRequest(FontQty uint16, Font []Str) []byte {
+func (c *Conn) setFontPathRequest(FontQty uint16, Font []Str) []byte {
 	size := pad((8 + StrListSize(Font)))
 	b := 0
 	buf := make([]byte, size)
@@ -9141,18 +9917,20 @@ func setFontPathRequest(FontQty uint16, Font []Str) []byte {
 
 // Request GetFontPath
 // size: 4
-type GetFontPathCookie cookie
+type GetFontPathCookie struct {
+	*cookie
+}
 
 func (c *Conn) GetFontPath() GetFontPathCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(getFontPathRequest(), cookie)
-	return GetFontPathCookie(cookie)
+	c.newRequest(c.getFontPathRequest(), cookie)
+	return GetFontPathCookie{cookie}
 }
 
 func (c *Conn) GetFontPathUnchecked() GetFontPathCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(getFontPathRequest(), cookie)
-	return GetFontPathCookie(cookie)
+	c.newRequest(c.getFontPathRequest(), cookie)
+	return GetFontPathCookie{cookie}
 }
 
 // Request reply for GetFontPath
@@ -9168,10 +9946,13 @@ type GetFontPathReply struct {
 
 // Waits and reads reply data from request GetFontPath
 func (cook GetFontPathCookie) Reply() (*GetFontPathReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return getFontPathReply(buf), nil
 }
 
@@ -9199,8 +9980,12 @@ func getFontPathReply(buf []byte) *GetFontPathReply {
 	return v
 }
 
+func (cook GetFontPathCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for GetFontPath
-func getFontPathRequest() []byte {
+func (c *Conn) getFontPathRequest() []byte {
 	size := 4
 	b := 0
 	buf := make([]byte, size)
@@ -9208,28 +9993,38 @@ func getFontPathRequest() []byte {
 	buf[b] = 52 // request opcode
 	b += 1
 
+	b += 1                         // padding
+	Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
+	b += 2
+
 	return buf
 }
 
 // Request CreatePixmap
 // size: 16
-type CreatePixmapCookie cookie
+type CreatePixmapCookie struct {
+	*cookie
+}
 
 // Write request to wire for CreatePixmap
 func (c *Conn) CreatePixmap(Depth byte, Pid Id, Drawable Id, Width uint16, Height uint16) CreatePixmapCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(createPixmapRequest(Depth, Pid, Drawable, Width, Height), cookie)
-	return CreatePixmapCookie(cookie)
+	c.newRequest(c.createPixmapRequest(Depth, Pid, Drawable, Width, Height), cookie)
+	return CreatePixmapCookie{cookie}
 }
 
 func (c *Conn) CreatePixmapChecked(Depth byte, Pid Id, Drawable Id, Width uint16, Height uint16) CreatePixmapCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(createPixmapRequest(Depth, Pid, Drawable, Width, Height), cookie)
-	return CreatePixmapCookie(cookie)
+	c.newRequest(c.createPixmapRequest(Depth, Pid, Drawable, Width, Height), cookie)
+	return CreatePixmapCookie{cookie}
+}
+
+func (cook CreatePixmapCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for CreatePixmap
-func createPixmapRequest(Depth byte, Pid Id, Drawable Id, Width uint16, Height uint16) []byte {
+func (c *Conn) createPixmapRequest(Depth byte, Pid Id, Drawable Id, Width uint16, Height uint16) []byte {
 	size := 16
 	b := 0
 	buf := make([]byte, size)
@@ -9260,23 +10055,29 @@ func createPixmapRequest(Depth byte, Pid Id, Drawable Id, Width uint16, Height u
 
 // Request FreePixmap
 // size: 8
-type FreePixmapCookie cookie
+type FreePixmapCookie struct {
+	*cookie
+}
 
 // Write request to wire for FreePixmap
 func (c *Conn) FreePixmap(Pixmap Id) FreePixmapCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(freePixmapRequest(Pixmap), cookie)
-	return FreePixmapCookie(cookie)
+	c.newRequest(c.freePixmapRequest(Pixmap), cookie)
+	return FreePixmapCookie{cookie}
 }
 
 func (c *Conn) FreePixmapChecked(Pixmap Id) FreePixmapCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(freePixmapRequest(Pixmap), cookie)
-	return FreePixmapCookie(cookie)
+	c.newRequest(c.freePixmapRequest(Pixmap), cookie)
+	return FreePixmapCookie{cookie}
+}
+
+func (cook FreePixmapCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for FreePixmap
-func freePixmapRequest(Pixmap Id) []byte {
+func (c *Conn) freePixmapRequest(Pixmap Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -9297,23 +10098,29 @@ func freePixmapRequest(Pixmap Id) []byte {
 
 // Request CreateGC
 // size: pad((12 + (4 + pad((4 * popCount(int(ValueMask)))))))
-type CreateGCCookie cookie
+type CreateGCCookie struct {
+	*cookie
+}
 
 // Write request to wire for CreateGC
 func (c *Conn) CreateGC(Cid Id, Drawable Id, ValueMask uint32, ValueList []uint32) CreateGCCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(createGCRequest(Cid, Drawable, ValueMask, ValueList), cookie)
-	return CreateGCCookie(cookie)
+	c.newRequest(c.createGCRequest(Cid, Drawable, ValueMask, ValueList), cookie)
+	return CreateGCCookie{cookie}
 }
 
 func (c *Conn) CreateGCChecked(Cid Id, Drawable Id, ValueMask uint32, ValueList []uint32) CreateGCCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(createGCRequest(Cid, Drawable, ValueMask, ValueList), cookie)
-	return CreateGCCookie(cookie)
+	c.newRequest(c.createGCRequest(Cid, Drawable, ValueMask, ValueList), cookie)
+	return CreateGCCookie{cookie}
+}
+
+func (cook CreateGCCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for CreateGC
-func createGCRequest(Cid Id, Drawable Id, ValueMask uint32, ValueList []uint32) []byte {
+func (c *Conn) createGCRequest(Cid Id, Drawable Id, ValueMask uint32, ValueList []uint32) []byte {
 	size := pad((12 + (4 + pad((4 * popCount(int(ValueMask)))))))
 	b := 0
 	buf := make([]byte, size)
@@ -9345,23 +10152,29 @@ func createGCRequest(Cid Id, Drawable Id, ValueMask uint32, ValueList []uint32)
 
 // Request ChangeGC
 // size: pad((8 + (4 + pad((4 * popCount(int(ValueMask)))))))
-type ChangeGCCookie cookie
+type ChangeGCCookie struct {
+	*cookie
+}
 
 // Write request to wire for ChangeGC
 func (c *Conn) ChangeGC(Gc Id, ValueMask uint32, ValueList []uint32) ChangeGCCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(changeGCRequest(Gc, ValueMask, ValueList), cookie)
-	return ChangeGCCookie(cookie)
+	c.newRequest(c.changeGCRequest(Gc, ValueMask, ValueList), cookie)
+	return ChangeGCCookie{cookie}
 }
 
 func (c *Conn) ChangeGCChecked(Gc Id, ValueMask uint32, ValueList []uint32) ChangeGCCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(changeGCRequest(Gc, ValueMask, ValueList), cookie)
-	return ChangeGCCookie(cookie)
+	c.newRequest(c.changeGCRequest(Gc, ValueMask, ValueList), cookie)
+	return ChangeGCCookie{cookie}
+}
+
+func (cook ChangeGCCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for ChangeGC
-func changeGCRequest(Gc Id, ValueMask uint32, ValueList []uint32) []byte {
+func (c *Conn) changeGCRequest(Gc Id, ValueMask uint32, ValueList []uint32) []byte {
 	size := pad((8 + (4 + pad((4 * popCount(int(ValueMask)))))))
 	b := 0
 	buf := make([]byte, size)
@@ -9390,23 +10203,29 @@ func changeGCRequest(Gc Id, ValueMask uint32, ValueList []uint32) []byte {
 
 // Request CopyGC
 // size: 16
-type CopyGCCookie cookie
+type CopyGCCookie struct {
+	*cookie
+}
 
 // Write request to wire for CopyGC
 func (c *Conn) CopyGC(SrcGc Id, DstGc Id, ValueMask uint32) CopyGCCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(copyGCRequest(SrcGc, DstGc, ValueMask), cookie)
-	return CopyGCCookie(cookie)
+	c.newRequest(c.copyGCRequest(SrcGc, DstGc, ValueMask), cookie)
+	return CopyGCCookie{cookie}
 }
 
 func (c *Conn) CopyGCChecked(SrcGc Id, DstGc Id, ValueMask uint32) CopyGCCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(copyGCRequest(SrcGc, DstGc, ValueMask), cookie)
-	return CopyGCCookie(cookie)
+	c.newRequest(c.copyGCRequest(SrcGc, DstGc, ValueMask), cookie)
+	return CopyGCCookie{cookie}
+}
+
+func (cook CopyGCCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for CopyGC
-func copyGCRequest(SrcGc Id, DstGc Id, ValueMask uint32) []byte {
+func (c *Conn) copyGCRequest(SrcGc Id, DstGc Id, ValueMask uint32) []byte {
 	size := 16
 	b := 0
 	buf := make([]byte, size)
@@ -9433,23 +10252,29 @@ func copyGCRequest(SrcGc Id, DstGc Id, ValueMask uint32) []byte {
 
 // Request SetDashes
 // size: pad((12 + pad((int(DashesLen) * 1))))
-type SetDashesCookie cookie
+type SetDashesCookie struct {
+	*cookie
+}
 
 // Write request to wire for SetDashes
 func (c *Conn) SetDashes(Gc Id, DashOffset uint16, DashesLen uint16, Dashes []byte) SetDashesCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(setDashesRequest(Gc, DashOffset, DashesLen, Dashes), cookie)
-	return SetDashesCookie(cookie)
+	c.newRequest(c.setDashesRequest(Gc, DashOffset, DashesLen, Dashes), cookie)
+	return SetDashesCookie{cookie}
 }
 
 func (c *Conn) SetDashesChecked(Gc Id, DashOffset uint16, DashesLen uint16, Dashes []byte) SetDashesCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(setDashesRequest(Gc, DashOffset, DashesLen, Dashes), cookie)
-	return SetDashesCookie(cookie)
+	c.newRequest(c.setDashesRequest(Gc, DashOffset, DashesLen, Dashes), cookie)
+	return SetDashesCookie{cookie}
+}
+
+func (cook SetDashesCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for SetDashes
-func setDashesRequest(Gc Id, DashOffset uint16, DashesLen uint16, Dashes []byte) []byte {
+func (c *Conn) setDashesRequest(Gc Id, DashOffset uint16, DashesLen uint16, Dashes []byte) []byte {
 	size := pad((12 + pad((int(DashesLen) * 1))))
 	b := 0
 	buf := make([]byte, size)
@@ -9479,23 +10304,29 @@ func setDashesRequest(Gc Id, DashOffset uint16, DashesLen uint16, Dashes []byte)
 
 // Request SetClipRectangles
 // size: pad((12 + pad((len(Rectangles) * 8))))
-type SetClipRectanglesCookie cookie
+type SetClipRectanglesCookie struct {
+	*cookie
+}
 
 // Write request to wire for SetClipRectangles
 func (c *Conn) SetClipRectangles(Ordering byte, Gc Id, ClipXOrigin int16, ClipYOrigin int16, Rectangles []Rectangle) SetClipRectanglesCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(setClipRectanglesRequest(Ordering, Gc, ClipXOrigin, ClipYOrigin, Rectangles), cookie)
-	return SetClipRectanglesCookie(cookie)
+	c.newRequest(c.setClipRectanglesRequest(Ordering, Gc, ClipXOrigin, ClipYOrigin, Rectangles), cookie)
+	return SetClipRectanglesCookie{cookie}
 }
 
 func (c *Conn) SetClipRectanglesChecked(Ordering byte, Gc Id, ClipXOrigin int16, ClipYOrigin int16, Rectangles []Rectangle) SetClipRectanglesCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(setClipRectanglesRequest(Ordering, Gc, ClipXOrigin, ClipYOrigin, Rectangles), cookie)
-	return SetClipRectanglesCookie(cookie)
+	c.newRequest(c.setClipRectanglesRequest(Ordering, Gc, ClipXOrigin, ClipYOrigin, Rectangles), cookie)
+	return SetClipRectanglesCookie{cookie}
+}
+
+func (cook SetClipRectanglesCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for SetClipRectangles
-func setClipRectanglesRequest(Ordering byte, Gc Id, ClipXOrigin int16, ClipYOrigin int16, Rectangles []Rectangle) []byte {
+func (c *Conn) setClipRectanglesRequest(Ordering byte, Gc Id, ClipXOrigin int16, ClipYOrigin int16, Rectangles []Rectangle) []byte {
 	size := pad((12 + pad((len(Rectangles) * 8))))
 	b := 0
 	buf := make([]byte, size)
@@ -9525,23 +10356,29 @@ func setClipRectanglesRequest(Ordering byte, Gc Id, ClipXOrigin int16, ClipYOrig
 
 // Request FreeGC
 // size: 8
-type FreeGCCookie cookie
+type FreeGCCookie struct {
+	*cookie
+}
 
 // Write request to wire for FreeGC
 func (c *Conn) FreeGC(Gc Id) FreeGCCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(freeGCRequest(Gc), cookie)
-	return FreeGCCookie(cookie)
+	c.newRequest(c.freeGCRequest(Gc), cookie)
+	return FreeGCCookie{cookie}
 }
 
 func (c *Conn) FreeGCChecked(Gc Id) FreeGCCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(freeGCRequest(Gc), cookie)
-	return FreeGCCookie(cookie)
+	c.newRequest(c.freeGCRequest(Gc), cookie)
+	return FreeGCCookie{cookie}
+}
+
+func (cook FreeGCCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for FreeGC
-func freeGCRequest(Gc Id) []byte {
+func (c *Conn) freeGCRequest(Gc Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -9562,23 +10399,29 @@ func freeGCRequest(Gc Id) []byte {
 
 // Request ClearArea
 // size: 16
-type ClearAreaCookie cookie
+type ClearAreaCookie struct {
+	*cookie
+}
 
 // Write request to wire for ClearArea
 func (c *Conn) ClearArea(Exposures bool, Window Id, X int16, Y int16, Width uint16, Height uint16) ClearAreaCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(clearAreaRequest(Exposures, Window, X, Y, Width, Height), cookie)
-	return ClearAreaCookie(cookie)
+	c.newRequest(c.clearAreaRequest(Exposures, Window, X, Y, Width, Height), cookie)
+	return ClearAreaCookie{cookie}
 }
 
 func (c *Conn) ClearAreaChecked(Exposures bool, Window Id, X int16, Y int16, Width uint16, Height uint16) ClearAreaCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(clearAreaRequest(Exposures, Window, X, Y, Width, Height), cookie)
-	return ClearAreaCookie(cookie)
+	c.newRequest(c.clearAreaRequest(Exposures, Window, X, Y, Width, Height), cookie)
+	return ClearAreaCookie{cookie}
+}
+
+func (cook ClearAreaCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for ClearArea
-func clearAreaRequest(Exposures bool, Window Id, X int16, Y int16, Width uint16, Height uint16) []byte {
+func (c *Conn) clearAreaRequest(Exposures bool, Window Id, X int16, Y int16, Width uint16, Height uint16) []byte {
 	size := 16
 	b := 0
 	buf := make([]byte, size)
@@ -9616,23 +10459,29 @@ func clearAreaRequest(Exposures bool, Window Id, X int16, Y int16, Width uint16,
 
 // Request CopyArea
 // size: 28
-type CopyAreaCookie cookie
+type CopyAreaCookie struct {
+	*cookie
+}
 
 // Write request to wire for CopyArea
 func (c *Conn) CopyArea(SrcDrawable Id, DstDrawable Id, Gc Id, SrcX int16, SrcY int16, DstX int16, DstY int16, Width uint16, Height uint16) CopyAreaCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(copyAreaRequest(SrcDrawable, DstDrawable, Gc, SrcX, SrcY, DstX, DstY, Width, Height), cookie)
-	return CopyAreaCookie(cookie)
+	c.newRequest(c.copyAreaRequest(SrcDrawable, DstDrawable, Gc, SrcX, SrcY, DstX, DstY, Width, Height), cookie)
+	return CopyAreaCookie{cookie}
 }
 
 func (c *Conn) CopyAreaChecked(SrcDrawable Id, DstDrawable Id, Gc Id, SrcX int16, SrcY int16, DstX int16, DstY int16, Width uint16, Height uint16) CopyAreaCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(copyAreaRequest(SrcDrawable, DstDrawable, Gc, SrcX, SrcY, DstX, DstY, Width, Height), cookie)
-	return CopyAreaCookie(cookie)
+	c.newRequest(c.copyAreaRequest(SrcDrawable, DstDrawable, Gc, SrcX, SrcY, DstX, DstY, Width, Height), cookie)
+	return CopyAreaCookie{cookie}
+}
+
+func (cook CopyAreaCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for CopyArea
-func copyAreaRequest(SrcDrawable Id, DstDrawable Id, Gc Id, SrcX int16, SrcY int16, DstX int16, DstY int16, Width uint16, Height uint16) []byte {
+func (c *Conn) copyAreaRequest(SrcDrawable Id, DstDrawable Id, Gc Id, SrcX int16, SrcY int16, DstX int16, DstY int16, Width uint16, Height uint16) []byte {
 	size := 28
 	b := 0
 	buf := make([]byte, size)
@@ -9677,23 +10526,29 @@ func copyAreaRequest(SrcDrawable Id, DstDrawable Id, Gc Id, SrcX int16, SrcY int
 
 // Request CopyPlane
 // size: 32
-type CopyPlaneCookie cookie
+type CopyPlaneCookie struct {
+	*cookie
+}
 
 // Write request to wire for CopyPlane
 func (c *Conn) CopyPlane(SrcDrawable Id, DstDrawable Id, Gc Id, SrcX int16, SrcY int16, DstX int16, DstY int16, Width uint16, Height uint16, BitPlane uint32) CopyPlaneCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(copyPlaneRequest(SrcDrawable, DstDrawable, Gc, SrcX, SrcY, DstX, DstY, Width, Height, BitPlane), cookie)
-	return CopyPlaneCookie(cookie)
+	c.newRequest(c.copyPlaneRequest(SrcDrawable, DstDrawable, Gc, SrcX, SrcY, DstX, DstY, Width, Height, BitPlane), cookie)
+	return CopyPlaneCookie{cookie}
 }
 
 func (c *Conn) CopyPlaneChecked(SrcDrawable Id, DstDrawable Id, Gc Id, SrcX int16, SrcY int16, DstX int16, DstY int16, Width uint16, Height uint16, BitPlane uint32) CopyPlaneCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(copyPlaneRequest(SrcDrawable, DstDrawable, Gc, SrcX, SrcY, DstX, DstY, Width, Height, BitPlane), cookie)
-	return CopyPlaneCookie(cookie)
+	c.newRequest(c.copyPlaneRequest(SrcDrawable, DstDrawable, Gc, SrcX, SrcY, DstX, DstY, Width, Height, BitPlane), cookie)
+	return CopyPlaneCookie{cookie}
+}
+
+func (cook CopyPlaneCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for CopyPlane
-func copyPlaneRequest(SrcDrawable Id, DstDrawable Id, Gc Id, SrcX int16, SrcY int16, DstX int16, DstY int16, Width uint16, Height uint16, BitPlane uint32) []byte {
+func (c *Conn) copyPlaneRequest(SrcDrawable Id, DstDrawable Id, Gc Id, SrcX int16, SrcY int16, DstX int16, DstY int16, Width uint16, Height uint16, BitPlane uint32) []byte {
 	size := 32
 	b := 0
 	buf := make([]byte, size)
@@ -9741,23 +10596,29 @@ func copyPlaneRequest(SrcDrawable Id, DstDrawable Id, Gc Id, SrcX int16, SrcY in
 
 // Request PolyPoint
 // size: pad((12 + pad((len(Points) * 4))))
-type PolyPointCookie cookie
+type PolyPointCookie struct {
+	*cookie
+}
 
 // Write request to wire for PolyPoint
 func (c *Conn) PolyPoint(CoordinateMode byte, Drawable Id, Gc Id, Points []Point) PolyPointCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(polyPointRequest(CoordinateMode, Drawable, Gc, Points), cookie)
-	return PolyPointCookie(cookie)
+	c.newRequest(c.polyPointRequest(CoordinateMode, Drawable, Gc, Points), cookie)
+	return PolyPointCookie{cookie}
 }
 
 func (c *Conn) PolyPointChecked(CoordinateMode byte, Drawable Id, Gc Id, Points []Point) PolyPointCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(polyPointRequest(CoordinateMode, Drawable, Gc, Points), cookie)
-	return PolyPointCookie(cookie)
+	c.newRequest(c.polyPointRequest(CoordinateMode, Drawable, Gc, Points), cookie)
+	return PolyPointCookie{cookie}
+}
+
+func (cook PolyPointCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for PolyPoint
-func polyPointRequest(CoordinateMode byte, Drawable Id, Gc Id, Points []Point) []byte {
+func (c *Conn) polyPointRequest(CoordinateMode byte, Drawable Id, Gc Id, Points []Point) []byte {
 	size := pad((12 + pad((len(Points) * 4))))
 	b := 0
 	buf := make([]byte, size)
@@ -9784,23 +10645,29 @@ func polyPointRequest(CoordinateMode byte, Drawable Id, Gc Id, Points []Point) [
 
 // Request PolyLine
 // size: pad((12 + pad((len(Points) * 4))))
-type PolyLineCookie cookie
+type PolyLineCookie struct {
+	*cookie
+}
 
 // Write request to wire for PolyLine
 func (c *Conn) PolyLine(CoordinateMode byte, Drawable Id, Gc Id, Points []Point) PolyLineCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(polyLineRequest(CoordinateMode, Drawable, Gc, Points), cookie)
-	return PolyLineCookie(cookie)
+	c.newRequest(c.polyLineRequest(CoordinateMode, Drawable, Gc, Points), cookie)
+	return PolyLineCookie{cookie}
 }
 
 func (c *Conn) PolyLineChecked(CoordinateMode byte, Drawable Id, Gc Id, Points []Point) PolyLineCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(polyLineRequest(CoordinateMode, Drawable, Gc, Points), cookie)
-	return PolyLineCookie(cookie)
+	c.newRequest(c.polyLineRequest(CoordinateMode, Drawable, Gc, Points), cookie)
+	return PolyLineCookie{cookie}
+}
+
+func (cook PolyLineCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for PolyLine
-func polyLineRequest(CoordinateMode byte, Drawable Id, Gc Id, Points []Point) []byte {
+func (c *Conn) polyLineRequest(CoordinateMode byte, Drawable Id, Gc Id, Points []Point) []byte {
 	size := pad((12 + pad((len(Points) * 4))))
 	b := 0
 	buf := make([]byte, size)
@@ -9827,23 +10694,29 @@ func polyLineRequest(CoordinateMode byte, Drawable Id, Gc Id, Points []Point) []
 
 // Request PolySegment
 // size: pad((12 + pad((len(Segments) * 8))))
-type PolySegmentCookie cookie
+type PolySegmentCookie struct {
+	*cookie
+}
 
 // Write request to wire for PolySegment
 func (c *Conn) PolySegment(Drawable Id, Gc Id, Segments []Segment) PolySegmentCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(polySegmentRequest(Drawable, Gc, Segments), cookie)
-	return PolySegmentCookie(cookie)
+	c.newRequest(c.polySegmentRequest(Drawable, Gc, Segments), cookie)
+	return PolySegmentCookie{cookie}
 }
 
 func (c *Conn) PolySegmentChecked(Drawable Id, Gc Id, Segments []Segment) PolySegmentCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(polySegmentRequest(Drawable, Gc, Segments), cookie)
-	return PolySegmentCookie(cookie)
+	c.newRequest(c.polySegmentRequest(Drawable, Gc, Segments), cookie)
+	return PolySegmentCookie{cookie}
+}
+
+func (cook PolySegmentCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for PolySegment
-func polySegmentRequest(Drawable Id, Gc Id, Segments []Segment) []byte {
+func (c *Conn) polySegmentRequest(Drawable Id, Gc Id, Segments []Segment) []byte {
 	size := pad((12 + pad((len(Segments) * 8))))
 	b := 0
 	buf := make([]byte, size)
@@ -9869,23 +10742,29 @@ func polySegmentRequest(Drawable Id, Gc Id, Segments []Segment) []byte {
 
 // Request PolyRectangle
 // size: pad((12 + pad((len(Rectangles) * 8))))
-type PolyRectangleCookie cookie
+type PolyRectangleCookie struct {
+	*cookie
+}
 
 // Write request to wire for PolyRectangle
 func (c *Conn) PolyRectangle(Drawable Id, Gc Id, Rectangles []Rectangle) PolyRectangleCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(polyRectangleRequest(Drawable, Gc, Rectangles), cookie)
-	return PolyRectangleCookie(cookie)
+	c.newRequest(c.polyRectangleRequest(Drawable, Gc, Rectangles), cookie)
+	return PolyRectangleCookie{cookie}
 }
 
 func (c *Conn) PolyRectangleChecked(Drawable Id, Gc Id, Rectangles []Rectangle) PolyRectangleCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(polyRectangleRequest(Drawable, Gc, Rectangles), cookie)
-	return PolyRectangleCookie(cookie)
+	c.newRequest(c.polyRectangleRequest(Drawable, Gc, Rectangles), cookie)
+	return PolyRectangleCookie{cookie}
+}
+
+func (cook PolyRectangleCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for PolyRectangle
-func polyRectangleRequest(Drawable Id, Gc Id, Rectangles []Rectangle) []byte {
+func (c *Conn) polyRectangleRequest(Drawable Id, Gc Id, Rectangles []Rectangle) []byte {
 	size := pad((12 + pad((len(Rectangles) * 8))))
 	b := 0
 	buf := make([]byte, size)
@@ -9911,23 +10790,29 @@ func polyRectangleRequest(Drawable Id, Gc Id, Rectangles []Rectangle) []byte {
 
 // Request PolyArc
 // size: pad((12 + pad((len(Arcs) * 12))))
-type PolyArcCookie cookie
+type PolyArcCookie struct {
+	*cookie
+}
 
 // Write request to wire for PolyArc
 func (c *Conn) PolyArc(Drawable Id, Gc Id, Arcs []Arc) PolyArcCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(polyArcRequest(Drawable, Gc, Arcs), cookie)
-	return PolyArcCookie(cookie)
+	c.newRequest(c.polyArcRequest(Drawable, Gc, Arcs), cookie)
+	return PolyArcCookie{cookie}
 }
 
 func (c *Conn) PolyArcChecked(Drawable Id, Gc Id, Arcs []Arc) PolyArcCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(polyArcRequest(Drawable, Gc, Arcs), cookie)
-	return PolyArcCookie(cookie)
+	c.newRequest(c.polyArcRequest(Drawable, Gc, Arcs), cookie)
+	return PolyArcCookie{cookie}
+}
+
+func (cook PolyArcCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for PolyArc
-func polyArcRequest(Drawable Id, Gc Id, Arcs []Arc) []byte {
+func (c *Conn) polyArcRequest(Drawable Id, Gc Id, Arcs []Arc) []byte {
 	size := pad((12 + pad((len(Arcs) * 12))))
 	b := 0
 	buf := make([]byte, size)
@@ -9953,23 +10838,29 @@ func polyArcRequest(Drawable Id, Gc Id, Arcs []Arc) []byte {
 
 // Request FillPoly
 // size: pad((16 + pad((len(Points) * 4))))
-type FillPolyCookie cookie
+type FillPolyCookie struct {
+	*cookie
+}
 
 // Write request to wire for FillPoly
 func (c *Conn) FillPoly(Drawable Id, Gc Id, Shape byte, CoordinateMode byte, Points []Point) FillPolyCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(fillPolyRequest(Drawable, Gc, Shape, CoordinateMode, Points), cookie)
-	return FillPolyCookie(cookie)
+	c.newRequest(c.fillPolyRequest(Drawable, Gc, Shape, CoordinateMode, Points), cookie)
+	return FillPolyCookie{cookie}
 }
 
 func (c *Conn) FillPolyChecked(Drawable Id, Gc Id, Shape byte, CoordinateMode byte, Points []Point) FillPolyCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(fillPolyRequest(Drawable, Gc, Shape, CoordinateMode, Points), cookie)
-	return FillPolyCookie(cookie)
+	c.newRequest(c.fillPolyRequest(Drawable, Gc, Shape, CoordinateMode, Points), cookie)
+	return FillPolyCookie{cookie}
+}
+
+func (cook FillPolyCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for FillPoly
-func fillPolyRequest(Drawable Id, Gc Id, Shape byte, CoordinateMode byte, Points []Point) []byte {
+func (c *Conn) fillPolyRequest(Drawable Id, Gc Id, Shape byte, CoordinateMode byte, Points []Point) []byte {
 	size := pad((16 + pad((len(Points) * 4))))
 	b := 0
 	buf := make([]byte, size)
@@ -10003,23 +10894,29 @@ func fillPolyRequest(Drawable Id, Gc Id, Shape byte, CoordinateMode byte, Points
 
 // Request PolyFillRectangle
 // size: pad((12 + pad((len(Rectangles) * 8))))
-type PolyFillRectangleCookie cookie
+type PolyFillRectangleCookie struct {
+	*cookie
+}
 
 // Write request to wire for PolyFillRectangle
 func (c *Conn) PolyFillRectangle(Drawable Id, Gc Id, Rectangles []Rectangle) PolyFillRectangleCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(polyFillRectangleRequest(Drawable, Gc, Rectangles), cookie)
-	return PolyFillRectangleCookie(cookie)
+	c.newRequest(c.polyFillRectangleRequest(Drawable, Gc, Rectangles), cookie)
+	return PolyFillRectangleCookie{cookie}
 }
 
 func (c *Conn) PolyFillRectangleChecked(Drawable Id, Gc Id, Rectangles []Rectangle) PolyFillRectangleCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(polyFillRectangleRequest(Drawable, Gc, Rectangles), cookie)
-	return PolyFillRectangleCookie(cookie)
+	c.newRequest(c.polyFillRectangleRequest(Drawable, Gc, Rectangles), cookie)
+	return PolyFillRectangleCookie{cookie}
+}
+
+func (cook PolyFillRectangleCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for PolyFillRectangle
-func polyFillRectangleRequest(Drawable Id, Gc Id, Rectangles []Rectangle) []byte {
+func (c *Conn) polyFillRectangleRequest(Drawable Id, Gc Id, Rectangles []Rectangle) []byte {
 	size := pad((12 + pad((len(Rectangles) * 8))))
 	b := 0
 	buf := make([]byte, size)
@@ -10045,23 +10942,29 @@ func polyFillRectangleRequest(Drawable Id, Gc Id, Rectangles []Rectangle) []byte
 
 // Request PolyFillArc
 // size: pad((12 + pad((len(Arcs) * 12))))
-type PolyFillArcCookie cookie
+type PolyFillArcCookie struct {
+	*cookie
+}
 
 // Write request to wire for PolyFillArc
 func (c *Conn) PolyFillArc(Drawable Id, Gc Id, Arcs []Arc) PolyFillArcCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(polyFillArcRequest(Drawable, Gc, Arcs), cookie)
-	return PolyFillArcCookie(cookie)
+	c.newRequest(c.polyFillArcRequest(Drawable, Gc, Arcs), cookie)
+	return PolyFillArcCookie{cookie}
 }
 
 func (c *Conn) PolyFillArcChecked(Drawable Id, Gc Id, Arcs []Arc) PolyFillArcCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(polyFillArcRequest(Drawable, Gc, Arcs), cookie)
-	return PolyFillArcCookie(cookie)
+	c.newRequest(c.polyFillArcRequest(Drawable, Gc, Arcs), cookie)
+	return PolyFillArcCookie{cookie}
+}
+
+func (cook PolyFillArcCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for PolyFillArc
-func polyFillArcRequest(Drawable Id, Gc Id, Arcs []Arc) []byte {
+func (c *Conn) polyFillArcRequest(Drawable Id, Gc Id, Arcs []Arc) []byte {
 	size := pad((12 + pad((len(Arcs) * 12))))
 	b := 0
 	buf := make([]byte, size)
@@ -10087,23 +10990,29 @@ func polyFillArcRequest(Drawable Id, Gc Id, Arcs []Arc) []byte {
 
 // Request PutImage
 // size: pad((24 + pad((len(Data) * 1))))
-type PutImageCookie cookie
+type PutImageCookie struct {
+	*cookie
+}
 
 // Write request to wire for PutImage
 func (c *Conn) PutImage(Format byte, Drawable Id, Gc Id, Width uint16, Height uint16, DstX int16, DstY int16, LeftPad byte, Depth byte, Data []byte) PutImageCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(putImageRequest(Format, Drawable, Gc, Width, Height, DstX, DstY, LeftPad, Depth, Data), cookie)
-	return PutImageCookie(cookie)
+	c.newRequest(c.putImageRequest(Format, Drawable, Gc, Width, Height, DstX, DstY, LeftPad, Depth, Data), cookie)
+	return PutImageCookie{cookie}
 }
 
 func (c *Conn) PutImageChecked(Format byte, Drawable Id, Gc Id, Width uint16, Height uint16, DstX int16, DstY int16, LeftPad byte, Depth byte, Data []byte) PutImageCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(putImageRequest(Format, Drawable, Gc, Width, Height, DstX, DstY, LeftPad, Depth, Data), cookie)
-	return PutImageCookie(cookie)
+	c.newRequest(c.putImageRequest(Format, Drawable, Gc, Width, Height, DstX, DstY, LeftPad, Depth, Data), cookie)
+	return PutImageCookie{cookie}
+}
+
+func (cook PutImageCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for PutImage
-func putImageRequest(Format byte, Drawable Id, Gc Id, Width uint16, Height uint16, DstX int16, DstY int16, LeftPad byte, Depth byte, Data []byte) []byte {
+func (c *Conn) putImageRequest(Format byte, Drawable Id, Gc Id, Width uint16, Height uint16, DstX int16, DstY int16, LeftPad byte, Depth byte, Data []byte) []byte {
 	size := pad((24 + pad((len(Data) * 1))))
 	b := 0
 	buf := make([]byte, size)
@@ -10151,18 +11060,20 @@ func putImageRequest(Format byte, Drawable Id, Gc Id, Width uint16, Height uint1
 
 // Request GetImage
 // size: 20
-type GetImageCookie cookie
+type GetImageCookie struct {
+	*cookie
+}
 
 func (c *Conn) GetImage(Format byte, Drawable Id, X int16, Y int16, Width uint16, Height uint16, PlaneMask uint32) GetImageCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(getImageRequest(Format, Drawable, X, Y, Width, Height, PlaneMask), cookie)
-	return GetImageCookie(cookie)
+	c.newRequest(c.getImageRequest(Format, Drawable, X, Y, Width, Height, PlaneMask), cookie)
+	return GetImageCookie{cookie}
 }
 
 func (c *Conn) GetImageUnchecked(Format byte, Drawable Id, X int16, Y int16, Width uint16, Height uint16, PlaneMask uint32) GetImageCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(getImageRequest(Format, Drawable, X, Y, Width, Height, PlaneMask), cookie)
-	return GetImageCookie(cookie)
+	c.newRequest(c.getImageRequest(Format, Drawable, X, Y, Width, Height, PlaneMask), cookie)
+	return GetImageCookie{cookie}
 }
 
 // Request reply for GetImage
@@ -10178,10 +11089,13 @@ type GetImageReply struct {
 
 // Waits and reads reply data from request GetImage
 func (cook GetImageCookie) Reply() (*GetImageReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return getImageReply(buf), nil
 }
 
@@ -10211,8 +11125,12 @@ func getImageReply(buf []byte) *GetImageReply {
 	return v
 }
 
+func (cook GetImageCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for GetImage
-func getImageRequest(Format byte, Drawable Id, X int16, Y int16, Width uint16, Height uint16, PlaneMask uint32) []byte {
+func (c *Conn) getImageRequest(Format byte, Drawable Id, X int16, Y int16, Width uint16, Height uint16, PlaneMask uint32) []byte {
 	size := 20
 	b := 0
 	buf := make([]byte, size)
@@ -10249,23 +11167,29 @@ func getImageRequest(Format byte, Drawable Id, X int16, Y int16, Width uint16, H
 
 // Request PolyText8
 // size: pad((16 + pad((len(Items) * 1))))
-type PolyText8Cookie cookie
+type PolyText8Cookie struct {
+	*cookie
+}
 
 // Write request to wire for PolyText8
 func (c *Conn) PolyText8(Drawable Id, Gc Id, X int16, Y int16, Items []byte) PolyText8Cookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(polyText8Request(Drawable, Gc, X, Y, Items), cookie)
-	return PolyText8Cookie(cookie)
+	c.newRequest(c.polyText8Request(Drawable, Gc, X, Y, Items), cookie)
+	return PolyText8Cookie{cookie}
 }
 
 func (c *Conn) PolyText8Checked(Drawable Id, Gc Id, X int16, Y int16, Items []byte) PolyText8Cookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(polyText8Request(Drawable, Gc, X, Y, Items), cookie)
-	return PolyText8Cookie(cookie)
+	c.newRequest(c.polyText8Request(Drawable, Gc, X, Y, Items), cookie)
+	return PolyText8Cookie{cookie}
+}
+
+func (cook PolyText8Cookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for PolyText8
-func polyText8Request(Drawable Id, Gc Id, X int16, Y int16, Items []byte) []byte {
+func (c *Conn) polyText8Request(Drawable Id, Gc Id, X int16, Y int16, Items []byte) []byte {
 	size := pad((16 + pad((len(Items) * 1))))
 	b := 0
 	buf := make([]byte, size)
@@ -10298,23 +11222,29 @@ func polyText8Request(Drawable Id, Gc Id, X int16, Y int16, Items []byte) []byte
 
 // Request PolyText16
 // size: pad((16 + pad((len(Items) * 1))))
-type PolyText16Cookie cookie
+type PolyText16Cookie struct {
+	*cookie
+}
 
 // Write request to wire for PolyText16
 func (c *Conn) PolyText16(Drawable Id, Gc Id, X int16, Y int16, Items []byte) PolyText16Cookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(polyText16Request(Drawable, Gc, X, Y, Items), cookie)
-	return PolyText16Cookie(cookie)
+	c.newRequest(c.polyText16Request(Drawable, Gc, X, Y, Items), cookie)
+	return PolyText16Cookie{cookie}
 }
 
 func (c *Conn) PolyText16Checked(Drawable Id, Gc Id, X int16, Y int16, Items []byte) PolyText16Cookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(polyText16Request(Drawable, Gc, X, Y, Items), cookie)
-	return PolyText16Cookie(cookie)
+	c.newRequest(c.polyText16Request(Drawable, Gc, X, Y, Items), cookie)
+	return PolyText16Cookie{cookie}
+}
+
+func (cook PolyText16Cookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for PolyText16
-func polyText16Request(Drawable Id, Gc Id, X int16, Y int16, Items []byte) []byte {
+func (c *Conn) polyText16Request(Drawable Id, Gc Id, X int16, Y int16, Items []byte) []byte {
 	size := pad((16 + pad((len(Items) * 1))))
 	b := 0
 	buf := make([]byte, size)
@@ -10347,23 +11277,29 @@ func polyText16Request(Drawable Id, Gc Id, X int16, Y int16, Items []byte) []byt
 
 // Request ImageText8
 // size: pad((16 + pad((int(StringLen) * 1))))
-type ImageText8Cookie cookie
+type ImageText8Cookie struct {
+	*cookie
+}
 
 // Write request to wire for ImageText8
 func (c *Conn) ImageText8(StringLen byte, Drawable Id, Gc Id, X int16, Y int16, String string) ImageText8Cookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(imageText8Request(StringLen, Drawable, Gc, X, Y, String), cookie)
-	return ImageText8Cookie(cookie)
+	c.newRequest(c.imageText8Request(StringLen, Drawable, Gc, X, Y, String), cookie)
+	return ImageText8Cookie{cookie}
 }
 
 func (c *Conn) ImageText8Checked(StringLen byte, Drawable Id, Gc Id, X int16, Y int16, String string) ImageText8Cookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(imageText8Request(StringLen, Drawable, Gc, X, Y, String), cookie)
-	return ImageText8Cookie(cookie)
+	c.newRequest(c.imageText8Request(StringLen, Drawable, Gc, X, Y, String), cookie)
+	return ImageText8Cookie{cookie}
+}
+
+func (cook ImageText8Cookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for ImageText8
-func imageText8Request(StringLen byte, Drawable Id, Gc Id, X int16, Y int16, String string) []byte {
+func (c *Conn) imageText8Request(StringLen byte, Drawable Id, Gc Id, X int16, Y int16, String string) []byte {
 	size := pad((16 + pad((int(StringLen) * 1))))
 	b := 0
 	buf := make([]byte, size)
@@ -10397,23 +11333,29 @@ func imageText8Request(StringLen byte, Drawable Id, Gc Id, X int16, Y int16, Str
 
 // Request ImageText16
 // size: pad((16 + pad((int(StringLen) * 2))))
-type ImageText16Cookie cookie
+type ImageText16Cookie struct {
+	*cookie
+}
 
 // Write request to wire for ImageText16
 func (c *Conn) ImageText16(StringLen byte, Drawable Id, Gc Id, X int16, Y int16, String []Char2b) ImageText16Cookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(imageText16Request(StringLen, Drawable, Gc, X, Y, String), cookie)
-	return ImageText16Cookie(cookie)
+	c.newRequest(c.imageText16Request(StringLen, Drawable, Gc, X, Y, String), cookie)
+	return ImageText16Cookie{cookie}
 }
 
 func (c *Conn) ImageText16Checked(StringLen byte, Drawable Id, Gc Id, X int16, Y int16, String []Char2b) ImageText16Cookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(imageText16Request(StringLen, Drawable, Gc, X, Y, String), cookie)
-	return ImageText16Cookie(cookie)
+	c.newRequest(c.imageText16Request(StringLen, Drawable, Gc, X, Y, String), cookie)
+	return ImageText16Cookie{cookie}
+}
+
+func (cook ImageText16Cookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for ImageText16
-func imageText16Request(StringLen byte, Drawable Id, Gc Id, X int16, Y int16, String []Char2b) []byte {
+func (c *Conn) imageText16Request(StringLen byte, Drawable Id, Gc Id, X int16, Y int16, String []Char2b) []byte {
 	size := pad((16 + pad((int(StringLen) * 2))))
 	b := 0
 	buf := make([]byte, size)
@@ -10446,23 +11388,29 @@ func imageText16Request(StringLen byte, Drawable Id, Gc Id, X int16, Y int16, St
 
 // Request CreateColormap
 // size: 16
-type CreateColormapCookie cookie
+type CreateColormapCookie struct {
+	*cookie
+}
 
 // Write request to wire for CreateColormap
 func (c *Conn) CreateColormap(Alloc byte, Mid Id, Window Id, Visual Visualid) CreateColormapCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(createColormapRequest(Alloc, Mid, Window, Visual), cookie)
-	return CreateColormapCookie(cookie)
+	c.newRequest(c.createColormapRequest(Alloc, Mid, Window, Visual), cookie)
+	return CreateColormapCookie{cookie}
 }
 
 func (c *Conn) CreateColormapChecked(Alloc byte, Mid Id, Window Id, Visual Visualid) CreateColormapCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(createColormapRequest(Alloc, Mid, Window, Visual), cookie)
-	return CreateColormapCookie(cookie)
+	c.newRequest(c.createColormapRequest(Alloc, Mid, Window, Visual), cookie)
+	return CreateColormapCookie{cookie}
+}
+
+func (cook CreateColormapCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for CreateColormap
-func createColormapRequest(Alloc byte, Mid Id, Window Id, Visual Visualid) []byte {
+func (c *Conn) createColormapRequest(Alloc byte, Mid Id, Window Id, Visual Visualid) []byte {
 	size := 16
 	b := 0
 	buf := make([]byte, size)
@@ -10490,23 +11438,29 @@ func createColormapRequest(Alloc byte, Mid Id, Window Id, Visual Visualid) []byt
 
 // Request FreeColormap
 // size: 8
-type FreeColormapCookie cookie
+type FreeColormapCookie struct {
+	*cookie
+}
 
 // Write request to wire for FreeColormap
 func (c *Conn) FreeColormap(Cmap Id) FreeColormapCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(freeColormapRequest(Cmap), cookie)
-	return FreeColormapCookie(cookie)
+	c.newRequest(c.freeColormapRequest(Cmap), cookie)
+	return FreeColormapCookie{cookie}
 }
 
 func (c *Conn) FreeColormapChecked(Cmap Id) FreeColormapCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(freeColormapRequest(Cmap), cookie)
-	return FreeColormapCookie(cookie)
+	c.newRequest(c.freeColormapRequest(Cmap), cookie)
+	return FreeColormapCookie{cookie}
+}
+
+func (cook FreeColormapCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for FreeColormap
-func freeColormapRequest(Cmap Id) []byte {
+func (c *Conn) freeColormapRequest(Cmap Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -10527,23 +11481,29 @@ func freeColormapRequest(Cmap Id) []byte {
 
 // Request CopyColormapAndFree
 // size: 12
-type CopyColormapAndFreeCookie cookie
+type CopyColormapAndFreeCookie struct {
+	*cookie
+}
 
 // Write request to wire for CopyColormapAndFree
 func (c *Conn) CopyColormapAndFree(Mid Id, SrcCmap Id) CopyColormapAndFreeCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(copyColormapAndFreeRequest(Mid, SrcCmap), cookie)
-	return CopyColormapAndFreeCookie(cookie)
+	c.newRequest(c.copyColormapAndFreeRequest(Mid, SrcCmap), cookie)
+	return CopyColormapAndFreeCookie{cookie}
 }
 
 func (c *Conn) CopyColormapAndFreeChecked(Mid Id, SrcCmap Id) CopyColormapAndFreeCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(copyColormapAndFreeRequest(Mid, SrcCmap), cookie)
-	return CopyColormapAndFreeCookie(cookie)
+	c.newRequest(c.copyColormapAndFreeRequest(Mid, SrcCmap), cookie)
+	return CopyColormapAndFreeCookie{cookie}
+}
+
+func (cook CopyColormapAndFreeCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for CopyColormapAndFree
-func copyColormapAndFreeRequest(Mid Id, SrcCmap Id) []byte {
+func (c *Conn) copyColormapAndFreeRequest(Mid Id, SrcCmap Id) []byte {
 	size := 12
 	b := 0
 	buf := make([]byte, size)
@@ -10567,23 +11527,29 @@ func copyColormapAndFreeRequest(Mid Id, SrcCmap Id) []byte {
 
 // Request InstallColormap
 // size: 8
-type InstallColormapCookie cookie
+type InstallColormapCookie struct {
+	*cookie
+}
 
 // Write request to wire for InstallColormap
 func (c *Conn) InstallColormap(Cmap Id) InstallColormapCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(installColormapRequest(Cmap), cookie)
-	return InstallColormapCookie(cookie)
+	c.newRequest(c.installColormapRequest(Cmap), cookie)
+	return InstallColormapCookie{cookie}
 }
 
 func (c *Conn) InstallColormapChecked(Cmap Id) InstallColormapCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(installColormapRequest(Cmap), cookie)
-	return InstallColormapCookie(cookie)
+	c.newRequest(c.installColormapRequest(Cmap), cookie)
+	return InstallColormapCookie{cookie}
+}
+
+func (cook InstallColormapCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for InstallColormap
-func installColormapRequest(Cmap Id) []byte {
+func (c *Conn) installColormapRequest(Cmap Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -10604,23 +11570,29 @@ func installColormapRequest(Cmap Id) []byte {
 
 // Request UninstallColormap
 // size: 8
-type UninstallColormapCookie cookie
+type UninstallColormapCookie struct {
+	*cookie
+}
 
 // Write request to wire for UninstallColormap
 func (c *Conn) UninstallColormap(Cmap Id) UninstallColormapCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(uninstallColormapRequest(Cmap), cookie)
-	return UninstallColormapCookie(cookie)
+	c.newRequest(c.uninstallColormapRequest(Cmap), cookie)
+	return UninstallColormapCookie{cookie}
 }
 
 func (c *Conn) UninstallColormapChecked(Cmap Id) UninstallColormapCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(uninstallColormapRequest(Cmap), cookie)
-	return UninstallColormapCookie(cookie)
+	c.newRequest(c.uninstallColormapRequest(Cmap), cookie)
+	return UninstallColormapCookie{cookie}
+}
+
+func (cook UninstallColormapCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for UninstallColormap
-func uninstallColormapRequest(Cmap Id) []byte {
+func (c *Conn) uninstallColormapRequest(Cmap Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -10641,18 +11613,20 @@ func uninstallColormapRequest(Cmap Id) []byte {
 
 // Request ListInstalledColormaps
 // size: 8
-type ListInstalledColormapsCookie cookie
+type ListInstalledColormapsCookie struct {
+	*cookie
+}
 
 func (c *Conn) ListInstalledColormaps(Window Id) ListInstalledColormapsCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(listInstalledColormapsRequest(Window), cookie)
-	return ListInstalledColormapsCookie(cookie)
+	c.newRequest(c.listInstalledColormapsRequest(Window), cookie)
+	return ListInstalledColormapsCookie{cookie}
 }
 
 func (c *Conn) ListInstalledColormapsUnchecked(Window Id) ListInstalledColormapsCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(listInstalledColormapsRequest(Window), cookie)
-	return ListInstalledColormapsCookie(cookie)
+	c.newRequest(c.listInstalledColormapsRequest(Window), cookie)
+	return ListInstalledColormapsCookie{cookie}
 }
 
 // Request reply for ListInstalledColormaps
@@ -10668,10 +11642,13 @@ type ListInstalledColormapsReply struct {
 
 // Waits and reads reply data from request ListInstalledColormaps
 func (cook ListInstalledColormapsCookie) Reply() (*ListInstalledColormapsReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return listInstalledColormapsReply(buf), nil
 }
 
@@ -10703,8 +11680,12 @@ func listInstalledColormapsReply(buf []byte) *ListInstalledColormapsReply {
 	return v
 }
 
+func (cook ListInstalledColormapsCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for ListInstalledColormaps
-func listInstalledColormapsRequest(Window Id) []byte {
+func (c *Conn) listInstalledColormapsRequest(Window Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -10725,18 +11706,20 @@ func listInstalledColormapsRequest(Window Id) []byte {
 
 // Request AllocColor
 // size: 16
-type AllocColorCookie cookie
+type AllocColorCookie struct {
+	*cookie
+}
 
 func (c *Conn) AllocColor(Cmap Id, Red uint16, Green uint16, Blue uint16) AllocColorCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(allocColorRequest(Cmap, Red, Green, Blue), cookie)
-	return AllocColorCookie(cookie)
+	c.newRequest(c.allocColorRequest(Cmap, Red, Green, Blue), cookie)
+	return AllocColorCookie{cookie}
 }
 
 func (c *Conn) AllocColorUnchecked(Cmap Id, Red uint16, Green uint16, Blue uint16) AllocColorCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(allocColorRequest(Cmap, Red, Green, Blue), cookie)
-	return AllocColorCookie(cookie)
+	c.newRequest(c.allocColorRequest(Cmap, Red, Green, Blue), cookie)
+	return AllocColorCookie{cookie}
 }
 
 // Request reply for AllocColor
@@ -10754,10 +11737,13 @@ type AllocColorReply struct {
 
 // Waits and reads reply data from request AllocColor
 func (cook AllocColorCookie) Reply() (*AllocColorReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return allocColorReply(buf), nil
 }
 
@@ -10791,8 +11777,12 @@ func allocColorReply(buf []byte) *AllocColorReply {
 	return v
 }
 
+func (cook AllocColorCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for AllocColor
-func allocColorRequest(Cmap Id, Red uint16, Green uint16, Blue uint16) []byte {
+func (c *Conn) allocColorRequest(Cmap Id, Red uint16, Green uint16, Blue uint16) []byte {
 	size := 16
 	b := 0
 	buf := make([]byte, size)
@@ -10824,18 +11814,20 @@ func allocColorRequest(Cmap Id, Red uint16, Green uint16, Blue uint16) []byte {
 
 // Request AllocNamedColor
 // size: pad((12 + pad((int(NameLen) * 1))))
-type AllocNamedColorCookie cookie
+type AllocNamedColorCookie struct {
+	*cookie
+}
 
 func (c *Conn) AllocNamedColor(Cmap Id, NameLen uint16, Name string) AllocNamedColorCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(allocNamedColorRequest(Cmap, NameLen, Name), cookie)
-	return AllocNamedColorCookie(cookie)
+	c.newRequest(c.allocNamedColorRequest(Cmap, NameLen, Name), cookie)
+	return AllocNamedColorCookie{cookie}
 }
 
 func (c *Conn) AllocNamedColorUnchecked(Cmap Id, NameLen uint16, Name string) AllocNamedColorCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(allocNamedColorRequest(Cmap, NameLen, Name), cookie)
-	return AllocNamedColorCookie(cookie)
+	c.newRequest(c.allocNamedColorRequest(Cmap, NameLen, Name), cookie)
+	return AllocNamedColorCookie{cookie}
 }
 
 // Request reply for AllocNamedColor
@@ -10855,10 +11847,13 @@ type AllocNamedColorReply struct {
 
 // Waits and reads reply data from request AllocNamedColor
 func (cook AllocNamedColorCookie) Reply() (*AllocNamedColorReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return allocNamedColorReply(buf), nil
 }
 
@@ -10899,8 +11894,12 @@ func allocNamedColorReply(buf []byte) *AllocNamedColorReply {
 	return v
 }
 
+func (cook AllocNamedColorCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for AllocNamedColor
-func allocNamedColorRequest(Cmap Id, NameLen uint16, Name string) []byte {
+func (c *Conn) allocNamedColorRequest(Cmap Id, NameLen uint16, Name string) []byte {
 	size := pad((12 + pad((int(NameLen) * 1))))
 	b := 0
 	buf := make([]byte, size)
@@ -10929,18 +11928,20 @@ func allocNamedColorRequest(Cmap Id, NameLen uint16, Name string) []byte {
 
 // Request AllocColorCells
 // size: 12
-type AllocColorCellsCookie cookie
+type AllocColorCellsCookie struct {
+	*cookie
+}
 
 func (c *Conn) AllocColorCells(Contiguous bool, Cmap Id, Colors uint16, Planes uint16) AllocColorCellsCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(allocColorCellsRequest(Contiguous, Cmap, Colors, Planes), cookie)
-	return AllocColorCellsCookie(cookie)
+	c.newRequest(c.allocColorCellsRequest(Contiguous, Cmap, Colors, Planes), cookie)
+	return AllocColorCellsCookie{cookie}
 }
 
 func (c *Conn) AllocColorCellsUnchecked(Contiguous bool, Cmap Id, Colors uint16, Planes uint16) AllocColorCellsCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(allocColorCellsRequest(Contiguous, Cmap, Colors, Planes), cookie)
-	return AllocColorCellsCookie(cookie)
+	c.newRequest(c.allocColorCellsRequest(Contiguous, Cmap, Colors, Planes), cookie)
+	return AllocColorCellsCookie{cookie}
 }
 
 // Request reply for AllocColorCells
@@ -10958,10 +11959,13 @@ type AllocColorCellsReply struct {
 
 // Waits and reads reply data from request AllocColorCells
 func (cook AllocColorCellsCookie) Reply() (*AllocColorCellsReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return allocColorCellsReply(buf), nil
 }
 
@@ -11003,8 +12007,12 @@ func allocColorCellsReply(buf []byte) *AllocColorCellsReply {
 	return v
 }
 
+func (cook AllocColorCellsCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for AllocColorCells
-func allocColorCellsRequest(Contiguous bool, Cmap Id, Colors uint16, Planes uint16) []byte {
+func (c *Conn) allocColorCellsRequest(Contiguous bool, Cmap Id, Colors uint16, Planes uint16) []byte {
 	size := 12
 	b := 0
 	buf := make([]byte, size)
@@ -11036,18 +12044,20 @@ func allocColorCellsRequest(Contiguous bool, Cmap Id, Colors uint16, Planes uint
 
 // Request AllocColorPlanes
 // size: 16
-type AllocColorPlanesCookie cookie
+type AllocColorPlanesCookie struct {
+	*cookie
+}
 
 func (c *Conn) AllocColorPlanes(Contiguous bool, Cmap Id, Colors uint16, Reds uint16, Greens uint16, Blues uint16) AllocColorPlanesCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(allocColorPlanesRequest(Contiguous, Cmap, Colors, Reds, Greens, Blues), cookie)
-	return AllocColorPlanesCookie(cookie)
+	c.newRequest(c.allocColorPlanesRequest(Contiguous, Cmap, Colors, Reds, Greens, Blues), cookie)
+	return AllocColorPlanesCookie{cookie}
 }
 
 func (c *Conn) AllocColorPlanesUnchecked(Contiguous bool, Cmap Id, Colors uint16, Reds uint16, Greens uint16, Blues uint16) AllocColorPlanesCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(allocColorPlanesRequest(Contiguous, Cmap, Colors, Reds, Greens, Blues), cookie)
-	return AllocColorPlanesCookie(cookie)
+	c.newRequest(c.allocColorPlanesRequest(Contiguous, Cmap, Colors, Reds, Greens, Blues), cookie)
+	return AllocColorPlanesCookie{cookie}
 }
 
 // Request reply for AllocColorPlanes
@@ -11067,10 +12077,13 @@ type AllocColorPlanesReply struct {
 
 // Waits and reads reply data from request AllocColorPlanes
 func (cook AllocColorPlanesCookie) Reply() (*AllocColorPlanesReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return allocColorPlanesReply(buf), nil
 }
 
@@ -11113,8 +12126,12 @@ func allocColorPlanesReply(buf []byte) *AllocColorPlanesReply {
 	return v
 }
 
+func (cook AllocColorPlanesCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for AllocColorPlanes
-func allocColorPlanesRequest(Contiguous bool, Cmap Id, Colors uint16, Reds uint16, Greens uint16, Blues uint16) []byte {
+func (c *Conn) allocColorPlanesRequest(Contiguous bool, Cmap Id, Colors uint16, Reds uint16, Greens uint16, Blues uint16) []byte {
 	size := 16
 	b := 0
 	buf := make([]byte, size)
@@ -11152,23 +12169,29 @@ func allocColorPlanesRequest(Contiguous bool, Cmap Id, Colors uint16, Reds uint1
 
 // Request FreeColors
 // size: pad((12 + pad((len(Pixels) * 4))))
-type FreeColorsCookie cookie
+type FreeColorsCookie struct {
+	*cookie
+}
 
 // Write request to wire for FreeColors
 func (c *Conn) FreeColors(Cmap Id, PlaneMask uint32, Pixels []uint32) FreeColorsCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(freeColorsRequest(Cmap, PlaneMask, Pixels), cookie)
-	return FreeColorsCookie(cookie)
+	c.newRequest(c.freeColorsRequest(Cmap, PlaneMask, Pixels), cookie)
+	return FreeColorsCookie{cookie}
 }
 
 func (c *Conn) FreeColorsChecked(Cmap Id, PlaneMask uint32, Pixels []uint32) FreeColorsCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(freeColorsRequest(Cmap, PlaneMask, Pixels), cookie)
-	return FreeColorsCookie(cookie)
+	c.newRequest(c.freeColorsRequest(Cmap, PlaneMask, Pixels), cookie)
+	return FreeColorsCookie{cookie}
+}
+
+func (cook FreeColorsCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for FreeColors
-func freeColorsRequest(Cmap Id, PlaneMask uint32, Pixels []uint32) []byte {
+func (c *Conn) freeColorsRequest(Cmap Id, PlaneMask uint32, Pixels []uint32) []byte {
 	size := pad((12 + pad((len(Pixels) * 4))))
 	b := 0
 	buf := make([]byte, size)
@@ -11198,23 +12221,29 @@ func freeColorsRequest(Cmap Id, PlaneMask uint32, Pixels []uint32) []byte {
 
 // Request StoreColors
 // size: pad((8 + pad((len(Items) * 12))))
-type StoreColorsCookie cookie
+type StoreColorsCookie struct {
+	*cookie
+}
 
 // Write request to wire for StoreColors
 func (c *Conn) StoreColors(Cmap Id, Items []Coloritem) StoreColorsCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(storeColorsRequest(Cmap, Items), cookie)
-	return StoreColorsCookie(cookie)
+	c.newRequest(c.storeColorsRequest(Cmap, Items), cookie)
+	return StoreColorsCookie{cookie}
 }
 
 func (c *Conn) StoreColorsChecked(Cmap Id, Items []Coloritem) StoreColorsCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(storeColorsRequest(Cmap, Items), cookie)
-	return StoreColorsCookie(cookie)
+	c.newRequest(c.storeColorsRequest(Cmap, Items), cookie)
+	return StoreColorsCookie{cookie}
+}
+
+func (cook StoreColorsCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for StoreColors
-func storeColorsRequest(Cmap Id, Items []Coloritem) []byte {
+func (c *Conn) storeColorsRequest(Cmap Id, Items []Coloritem) []byte {
 	size := pad((8 + pad((len(Items) * 12))))
 	b := 0
 	buf := make([]byte, size)
@@ -11237,23 +12266,29 @@ func storeColorsRequest(Cmap Id, Items []Coloritem) []byte {
 
 // Request StoreNamedColor
 // size: pad((16 + pad((int(NameLen) * 1))))
-type StoreNamedColorCookie cookie
+type StoreNamedColorCookie struct {
+	*cookie
+}
 
 // Write request to wire for StoreNamedColor
 func (c *Conn) StoreNamedColor(Flags byte, Cmap Id, Pixel uint32, NameLen uint16, Name string) StoreNamedColorCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(storeNamedColorRequest(Flags, Cmap, Pixel, NameLen, Name), cookie)
-	return StoreNamedColorCookie(cookie)
+	c.newRequest(c.storeNamedColorRequest(Flags, Cmap, Pixel, NameLen, Name), cookie)
+	return StoreNamedColorCookie{cookie}
 }
 
 func (c *Conn) StoreNamedColorChecked(Flags byte, Cmap Id, Pixel uint32, NameLen uint16, Name string) StoreNamedColorCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(storeNamedColorRequest(Flags, Cmap, Pixel, NameLen, Name), cookie)
-	return StoreNamedColorCookie(cookie)
+	c.newRequest(c.storeNamedColorRequest(Flags, Cmap, Pixel, NameLen, Name), cookie)
+	return StoreNamedColorCookie{cookie}
+}
+
+func (cook StoreNamedColorCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for StoreNamedColor
-func storeNamedColorRequest(Flags byte, Cmap Id, Pixel uint32, NameLen uint16, Name string) []byte {
+func (c *Conn) storeNamedColorRequest(Flags byte, Cmap Id, Pixel uint32, NameLen uint16, Name string) []byte {
 	size := pad((16 + pad((int(NameLen) * 1))))
 	b := 0
 	buf := make([]byte, size)
@@ -11286,18 +12321,20 @@ func storeNamedColorRequest(Flags byte, Cmap Id, Pixel uint32, NameLen uint16, N
 
 // Request QueryColors
 // size: pad((8 + pad((len(Pixels) * 4))))
-type QueryColorsCookie cookie
+type QueryColorsCookie struct {
+	*cookie
+}
 
 func (c *Conn) QueryColors(Cmap Id, Pixels []uint32) QueryColorsCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(queryColorsRequest(Cmap, Pixels), cookie)
-	return QueryColorsCookie(cookie)
+	c.newRequest(c.queryColorsRequest(Cmap, Pixels), cookie)
+	return QueryColorsCookie{cookie}
 }
 
 func (c *Conn) QueryColorsUnchecked(Cmap Id, Pixels []uint32) QueryColorsCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(queryColorsRequest(Cmap, Pixels), cookie)
-	return QueryColorsCookie(cookie)
+	c.newRequest(c.queryColorsRequest(Cmap, Pixels), cookie)
+	return QueryColorsCookie{cookie}
 }
 
 // Request reply for QueryColors
@@ -11313,10 +12350,13 @@ type QueryColorsReply struct {
 
 // Waits and reads reply data from request QueryColors
 func (cook QueryColorsCookie) Reply() (*QueryColorsReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return queryColorsReply(buf), nil
 }
 
@@ -11344,8 +12384,12 @@ func queryColorsReply(buf []byte) *QueryColorsReply {
 	return v
 }
 
+func (cook QueryColorsCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for QueryColors
-func queryColorsRequest(Cmap Id, Pixels []uint32) []byte {
+func (c *Conn) queryColorsRequest(Cmap Id, Pixels []uint32) []byte {
 	size := pad((8 + pad((len(Pixels) * 4))))
 	b := 0
 	buf := make([]byte, size)
@@ -11372,18 +12416,20 @@ func queryColorsRequest(Cmap Id, Pixels []uint32) []byte {
 
 // Request LookupColor
 // size: pad((12 + pad((int(NameLen) * 1))))
-type LookupColorCookie cookie
+type LookupColorCookie struct {
+	*cookie
+}
 
 func (c *Conn) LookupColor(Cmap Id, NameLen uint16, Name string) LookupColorCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(lookupColorRequest(Cmap, NameLen, Name), cookie)
-	return LookupColorCookie(cookie)
+	c.newRequest(c.lookupColorRequest(Cmap, NameLen, Name), cookie)
+	return LookupColorCookie{cookie}
 }
 
 func (c *Conn) LookupColorUnchecked(Cmap Id, NameLen uint16, Name string) LookupColorCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(lookupColorRequest(Cmap, NameLen, Name), cookie)
-	return LookupColorCookie(cookie)
+	c.newRequest(c.lookupColorRequest(Cmap, NameLen, Name), cookie)
+	return LookupColorCookie{cookie}
 }
 
 // Request reply for LookupColor
@@ -11402,10 +12448,13 @@ type LookupColorReply struct {
 
 // Waits and reads reply data from request LookupColor
 func (cook LookupColorCookie) Reply() (*LookupColorReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return lookupColorReply(buf), nil
 }
 
@@ -11443,8 +12492,12 @@ func lookupColorReply(buf []byte) *LookupColorReply {
 	return v
 }
 
+func (cook LookupColorCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for LookupColor
-func lookupColorRequest(Cmap Id, NameLen uint16, Name string) []byte {
+func (c *Conn) lookupColorRequest(Cmap Id, NameLen uint16, Name string) []byte {
 	size := pad((12 + pad((int(NameLen) * 1))))
 	b := 0
 	buf := make([]byte, size)
@@ -11473,23 +12526,29 @@ func lookupColorRequest(Cmap Id, NameLen uint16, Name string) []byte {
 
 // Request CreateCursor
 // size: 32
-type CreateCursorCookie cookie
+type CreateCursorCookie struct {
+	*cookie
+}
 
 // Write request to wire for CreateCursor
 func (c *Conn) CreateCursor(Cid Id, Source Id, Mask Id, ForeRed uint16, ForeGreen uint16, ForeBlue uint16, BackRed uint16, BackGreen uint16, BackBlue uint16, X uint16, Y uint16) CreateCursorCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(createCursorRequest(Cid, Source, Mask, ForeRed, ForeGreen, ForeBlue, BackRed, BackGreen, BackBlue, X, Y), cookie)
-	return CreateCursorCookie(cookie)
+	c.newRequest(c.createCursorRequest(Cid, Source, Mask, ForeRed, ForeGreen, ForeBlue, BackRed, BackGreen, BackBlue, X, Y), cookie)
+	return CreateCursorCookie{cookie}
 }
 
 func (c *Conn) CreateCursorChecked(Cid Id, Source Id, Mask Id, ForeRed uint16, ForeGreen uint16, ForeBlue uint16, BackRed uint16, BackGreen uint16, BackBlue uint16, X uint16, Y uint16) CreateCursorCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(createCursorRequest(Cid, Source, Mask, ForeRed, ForeGreen, ForeBlue, BackRed, BackGreen, BackBlue, X, Y), cookie)
-	return CreateCursorCookie(cookie)
+	c.newRequest(c.createCursorRequest(Cid, Source, Mask, ForeRed, ForeGreen, ForeBlue, BackRed, BackGreen, BackBlue, X, Y), cookie)
+	return CreateCursorCookie{cookie}
+}
+
+func (cook CreateCursorCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for CreateCursor
-func createCursorRequest(Cid Id, Source Id, Mask Id, ForeRed uint16, ForeGreen uint16, ForeBlue uint16, BackRed uint16, BackGreen uint16, BackBlue uint16, X uint16, Y uint16) []byte {
+func (c *Conn) createCursorRequest(Cid Id, Source Id, Mask Id, ForeRed uint16, ForeGreen uint16, ForeBlue uint16, BackRed uint16, BackGreen uint16, BackBlue uint16, X uint16, Y uint16) []byte {
 	size := 32
 	b := 0
 	buf := make([]byte, size)
@@ -11540,23 +12599,29 @@ func createCursorRequest(Cid Id, Source Id, Mask Id, ForeRed uint16, ForeGreen u
 
 // Request CreateGlyphCursor
 // size: 32
-type CreateGlyphCursorCookie cookie
+type CreateGlyphCursorCookie struct {
+	*cookie
+}
 
 // Write request to wire for CreateGlyphCursor
 func (c *Conn) CreateGlyphCursor(Cid Id, SourceFont Id, MaskFont Id, SourceChar uint16, MaskChar uint16, ForeRed uint16, ForeGreen uint16, ForeBlue uint16, BackRed uint16, BackGreen uint16, BackBlue uint16) CreateGlyphCursorCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(createGlyphCursorRequest(Cid, SourceFont, MaskFont, SourceChar, MaskChar, ForeRed, ForeGreen, ForeBlue, BackRed, BackGreen, BackBlue), cookie)
-	return CreateGlyphCursorCookie(cookie)
+	c.newRequest(c.createGlyphCursorRequest(Cid, SourceFont, MaskFont, SourceChar, MaskChar, ForeRed, ForeGreen, ForeBlue, BackRed, BackGreen, BackBlue), cookie)
+	return CreateGlyphCursorCookie{cookie}
 }
 
 func (c *Conn) CreateGlyphCursorChecked(Cid Id, SourceFont Id, MaskFont Id, SourceChar uint16, MaskChar uint16, ForeRed uint16, ForeGreen uint16, ForeBlue uint16, BackRed uint16, BackGreen uint16, BackBlue uint16) CreateGlyphCursorCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(createGlyphCursorRequest(Cid, SourceFont, MaskFont, SourceChar, MaskChar, ForeRed, ForeGreen, ForeBlue, BackRed, BackGreen, BackBlue), cookie)
-	return CreateGlyphCursorCookie(cookie)
+	c.newRequest(c.createGlyphCursorRequest(Cid, SourceFont, MaskFont, SourceChar, MaskChar, ForeRed, ForeGreen, ForeBlue, BackRed, BackGreen, BackBlue), cookie)
+	return CreateGlyphCursorCookie{cookie}
+}
+
+func (cook CreateGlyphCursorCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for CreateGlyphCursor
-func createGlyphCursorRequest(Cid Id, SourceFont Id, MaskFont Id, SourceChar uint16, MaskChar uint16, ForeRed uint16, ForeGreen uint16, ForeBlue uint16, BackRed uint16, BackGreen uint16, BackBlue uint16) []byte {
+func (c *Conn) createGlyphCursorRequest(Cid Id, SourceFont Id, MaskFont Id, SourceChar uint16, MaskChar uint16, ForeRed uint16, ForeGreen uint16, ForeBlue uint16, BackRed uint16, BackGreen uint16, BackBlue uint16) []byte {
 	size := 32
 	b := 0
 	buf := make([]byte, size)
@@ -11607,23 +12672,29 @@ func createGlyphCursorRequest(Cid Id, SourceFont Id, MaskFont Id, SourceChar uin
 
 // Request FreeCursor
 // size: 8
-type FreeCursorCookie cookie
+type FreeCursorCookie struct {
+	*cookie
+}
 
 // Write request to wire for FreeCursor
 func (c *Conn) FreeCursor(Cursor Id) FreeCursorCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(freeCursorRequest(Cursor), cookie)
-	return FreeCursorCookie(cookie)
+	c.newRequest(c.freeCursorRequest(Cursor), cookie)
+	return FreeCursorCookie{cookie}
 }
 
 func (c *Conn) FreeCursorChecked(Cursor Id) FreeCursorCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(freeCursorRequest(Cursor), cookie)
-	return FreeCursorCookie(cookie)
+	c.newRequest(c.freeCursorRequest(Cursor), cookie)
+	return FreeCursorCookie{cookie}
+}
+
+func (cook FreeCursorCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for FreeCursor
-func freeCursorRequest(Cursor Id) []byte {
+func (c *Conn) freeCursorRequest(Cursor Id) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -11644,23 +12715,29 @@ func freeCursorRequest(Cursor Id) []byte {
 
 // Request RecolorCursor
 // size: 20
-type RecolorCursorCookie cookie
+type RecolorCursorCookie struct {
+	*cookie
+}
 
 // Write request to wire for RecolorCursor
 func (c *Conn) RecolorCursor(Cursor Id, ForeRed uint16, ForeGreen uint16, ForeBlue uint16, BackRed uint16, BackGreen uint16, BackBlue uint16) RecolorCursorCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(recolorCursorRequest(Cursor, ForeRed, ForeGreen, ForeBlue, BackRed, BackGreen, BackBlue), cookie)
-	return RecolorCursorCookie(cookie)
+	c.newRequest(c.recolorCursorRequest(Cursor, ForeRed, ForeGreen, ForeBlue, BackRed, BackGreen, BackBlue), cookie)
+	return RecolorCursorCookie{cookie}
 }
 
 func (c *Conn) RecolorCursorChecked(Cursor Id, ForeRed uint16, ForeGreen uint16, ForeBlue uint16, BackRed uint16, BackGreen uint16, BackBlue uint16) RecolorCursorCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(recolorCursorRequest(Cursor, ForeRed, ForeGreen, ForeBlue, BackRed, BackGreen, BackBlue), cookie)
-	return RecolorCursorCookie(cookie)
+	c.newRequest(c.recolorCursorRequest(Cursor, ForeRed, ForeGreen, ForeBlue, BackRed, BackGreen, BackBlue), cookie)
+	return RecolorCursorCookie{cookie}
+}
+
+func (cook RecolorCursorCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for RecolorCursor
-func recolorCursorRequest(Cursor Id, ForeRed uint16, ForeGreen uint16, ForeBlue uint16, BackRed uint16, BackGreen uint16, BackBlue uint16) []byte {
+func (c *Conn) recolorCursorRequest(Cursor Id, ForeRed uint16, ForeGreen uint16, ForeBlue uint16, BackRed uint16, BackGreen uint16, BackBlue uint16) []byte {
 	size := 20
 	b := 0
 	buf := make([]byte, size)
@@ -11699,18 +12776,20 @@ func recolorCursorRequest(Cursor Id, ForeRed uint16, ForeGreen uint16, ForeBlue
 
 // Request QueryBestSize
 // size: 12
-type QueryBestSizeCookie cookie
+type QueryBestSizeCookie struct {
+	*cookie
+}
 
 func (c *Conn) QueryBestSize(Class byte, Drawable Id, Width uint16, Height uint16) QueryBestSizeCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(queryBestSizeRequest(Class, Drawable, Width, Height), cookie)
-	return QueryBestSizeCookie(cookie)
+	c.newRequest(c.queryBestSizeRequest(Class, Drawable, Width, Height), cookie)
+	return QueryBestSizeCookie{cookie}
 }
 
 func (c *Conn) QueryBestSizeUnchecked(Class byte, Drawable Id, Width uint16, Height uint16) QueryBestSizeCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(queryBestSizeRequest(Class, Drawable, Width, Height), cookie)
-	return QueryBestSizeCookie(cookie)
+	c.newRequest(c.queryBestSizeRequest(Class, Drawable, Width, Height), cookie)
+	return QueryBestSizeCookie{cookie}
 }
 
 // Request reply for QueryBestSize
@@ -11725,10 +12804,13 @@ type QueryBestSizeReply struct {
 
 // Waits and reads reply data from request QueryBestSize
 func (cook QueryBestSizeCookie) Reply() (*QueryBestSizeReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return queryBestSizeReply(buf), nil
 }
 
@@ -11754,8 +12836,12 @@ func queryBestSizeReply(buf []byte) *QueryBestSizeReply {
 	return v
 }
 
+func (cook QueryBestSizeCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for QueryBestSize
-func queryBestSizeRequest(Class byte, Drawable Id, Width uint16, Height uint16) []byte {
+func (c *Conn) queryBestSizeRequest(Class byte, Drawable Id, Width uint16, Height uint16) []byte {
 	size := 12
 	b := 0
 	buf := make([]byte, size)
@@ -11783,18 +12869,20 @@ func queryBestSizeRequest(Class byte, Drawable Id, Width uint16, Height uint16)
 
 // Request QueryExtension
 // size: pad((8 + pad((int(NameLen) * 1))))
-type QueryExtensionCookie cookie
+type QueryExtensionCookie struct {
+	*cookie
+}
 
 func (c *Conn) QueryExtension(NameLen uint16, Name string) QueryExtensionCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(queryExtensionRequest(NameLen, Name), cookie)
-	return QueryExtensionCookie(cookie)
+	c.newRequest(c.queryExtensionRequest(NameLen, Name), cookie)
+	return QueryExtensionCookie{cookie}
 }
 
 func (c *Conn) QueryExtensionUnchecked(NameLen uint16, Name string) QueryExtensionCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(queryExtensionRequest(NameLen, Name), cookie)
-	return QueryExtensionCookie(cookie)
+	c.newRequest(c.queryExtensionRequest(NameLen, Name), cookie)
+	return QueryExtensionCookie{cookie}
 }
 
 // Request reply for QueryExtension
@@ -11811,10 +12899,13 @@ type QueryExtensionReply struct {
 
 // Waits and reads reply data from request QueryExtension
 func (cook QueryExtensionCookie) Reply() (*QueryExtensionReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return queryExtensionReply(buf), nil
 }
 
@@ -11850,8 +12941,12 @@ func queryExtensionReply(buf []byte) *QueryExtensionReply {
 	return v
 }
 
+func (cook QueryExtensionCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for QueryExtension
-func queryExtensionRequest(NameLen uint16, Name string) []byte {
+func (c *Conn) queryExtensionRequest(NameLen uint16, Name string) []byte {
 	size := pad((8 + pad((int(NameLen) * 1))))
 	b := 0
 	buf := make([]byte, size)
@@ -11877,18 +12972,20 @@ func queryExtensionRequest(NameLen uint16, Name string) []byte {
 
 // Request ListExtensions
 // size: 4
-type ListExtensionsCookie cookie
+type ListExtensionsCookie struct {
+	*cookie
+}
 
 func (c *Conn) ListExtensions() ListExtensionsCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(listExtensionsRequest(), cookie)
-	return ListExtensionsCookie(cookie)
+	c.newRequest(c.listExtensionsRequest(), cookie)
+	return ListExtensionsCookie{cookie}
 }
 
 func (c *Conn) ListExtensionsUnchecked() ListExtensionsCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(listExtensionsRequest(), cookie)
-	return ListExtensionsCookie(cookie)
+	c.newRequest(c.listExtensionsRequest(), cookie)
+	return ListExtensionsCookie{cookie}
 }
 
 // Request reply for ListExtensions
@@ -11903,10 +13000,13 @@ type ListExtensionsReply struct {
 
 // Waits and reads reply data from request ListExtensions
 func (cook ListExtensionsCookie) Reply() (*ListExtensionsReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return listExtensionsReply(buf), nil
 }
 
@@ -11932,8 +13032,12 @@ func listExtensionsReply(buf []byte) *ListExtensionsReply {
 	return v
 }
 
+func (cook ListExtensionsCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for ListExtensions
-func listExtensionsRequest() []byte {
+func (c *Conn) listExtensionsRequest() []byte {
 	size := 4
 	b := 0
 	buf := make([]byte, size)
@@ -11941,28 +13045,38 @@ func listExtensionsRequest() []byte {
 	buf[b] = 99 // request opcode
 	b += 1
 
+	b += 1                         // padding
+	Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
+	b += 2
+
 	return buf
 }
 
 // Request ChangeKeyboardMapping
 // size: pad((8 + pad(((int(KeycodeCount) * int(KeysymsPerKeycode)) * 4))))
-type ChangeKeyboardMappingCookie cookie
+type ChangeKeyboardMappingCookie struct {
+	*cookie
+}
 
 // Write request to wire for ChangeKeyboardMapping
 func (c *Conn) ChangeKeyboardMapping(KeycodeCount byte, FirstKeycode Keycode, KeysymsPerKeycode byte, Keysyms []Keysym) ChangeKeyboardMappingCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(changeKeyboardMappingRequest(KeycodeCount, FirstKeycode, KeysymsPerKeycode, Keysyms), cookie)
-	return ChangeKeyboardMappingCookie(cookie)
+	c.newRequest(c.changeKeyboardMappingRequest(KeycodeCount, FirstKeycode, KeysymsPerKeycode, Keysyms), cookie)
+	return ChangeKeyboardMappingCookie{cookie}
 }
 
 func (c *Conn) ChangeKeyboardMappingChecked(KeycodeCount byte, FirstKeycode Keycode, KeysymsPerKeycode byte, Keysyms []Keysym) ChangeKeyboardMappingCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(changeKeyboardMappingRequest(KeycodeCount, FirstKeycode, KeysymsPerKeycode, Keysyms), cookie)
-	return ChangeKeyboardMappingCookie(cookie)
+	c.newRequest(c.changeKeyboardMappingRequest(KeycodeCount, FirstKeycode, KeysymsPerKeycode, Keysyms), cookie)
+	return ChangeKeyboardMappingCookie{cookie}
+}
+
+func (cook ChangeKeyboardMappingCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for ChangeKeyboardMapping
-func changeKeyboardMappingRequest(KeycodeCount byte, FirstKeycode Keycode, KeysymsPerKeycode byte, Keysyms []Keysym) []byte {
+func (c *Conn) changeKeyboardMappingRequest(KeycodeCount byte, FirstKeycode Keycode, KeysymsPerKeycode byte, Keysyms []Keysym) []byte {
 	size := pad((8 + pad(((int(KeycodeCount) * int(KeysymsPerKeycode)) * 4))))
 	b := 0
 	buf := make([]byte, size)
@@ -11995,18 +13109,20 @@ func changeKeyboardMappingRequest(KeycodeCount byte, FirstKeycode Keycode, Keysy
 
 // Request GetKeyboardMapping
 // size: 8
-type GetKeyboardMappingCookie cookie
+type GetKeyboardMappingCookie struct {
+	*cookie
+}
 
 func (c *Conn) GetKeyboardMapping(FirstKeycode Keycode, Count byte) GetKeyboardMappingCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(getKeyboardMappingRequest(FirstKeycode, Count), cookie)
-	return GetKeyboardMappingCookie(cookie)
+	c.newRequest(c.getKeyboardMappingRequest(FirstKeycode, Count), cookie)
+	return GetKeyboardMappingCookie{cookie}
 }
 
 func (c *Conn) GetKeyboardMappingUnchecked(FirstKeycode Keycode, Count byte) GetKeyboardMappingCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(getKeyboardMappingRequest(FirstKeycode, Count), cookie)
-	return GetKeyboardMappingCookie(cookie)
+	c.newRequest(c.getKeyboardMappingRequest(FirstKeycode, Count), cookie)
+	return GetKeyboardMappingCookie{cookie}
 }
 
 // Request reply for GetKeyboardMapping
@@ -12021,10 +13137,13 @@ type GetKeyboardMappingReply struct {
 
 // Waits and reads reply data from request GetKeyboardMapping
 func (cook GetKeyboardMappingCookie) Reply() (*GetKeyboardMappingReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return getKeyboardMappingReply(buf), nil
 }
 
@@ -12054,8 +13173,12 @@ func getKeyboardMappingReply(buf []byte) *GetKeyboardMappingReply {
 	return v
 }
 
+func (cook GetKeyboardMappingCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for GetKeyboardMapping
-func getKeyboardMappingRequest(FirstKeycode Keycode, Count byte) []byte {
+func (c *Conn) getKeyboardMappingRequest(FirstKeycode Keycode, Count byte) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -12079,23 +13202,29 @@ func getKeyboardMappingRequest(FirstKeycode Keycode, Count byte) []byte {
 
 // Request ChangeKeyboardControl
 // size: pad((4 + (4 + pad((4 * popCount(int(ValueMask)))))))
-type ChangeKeyboardControlCookie cookie
+type ChangeKeyboardControlCookie struct {
+	*cookie
+}
 
 // Write request to wire for ChangeKeyboardControl
 func (c *Conn) ChangeKeyboardControl(ValueMask uint32, ValueList []uint32) ChangeKeyboardControlCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(changeKeyboardControlRequest(ValueMask, ValueList), cookie)
-	return ChangeKeyboardControlCookie(cookie)
+	c.newRequest(c.changeKeyboardControlRequest(ValueMask, ValueList), cookie)
+	return ChangeKeyboardControlCookie{cookie}
 }
 
 func (c *Conn) ChangeKeyboardControlChecked(ValueMask uint32, ValueList []uint32) ChangeKeyboardControlCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(changeKeyboardControlRequest(ValueMask, ValueList), cookie)
-	return ChangeKeyboardControlCookie(cookie)
+	c.newRequest(c.changeKeyboardControlRequest(ValueMask, ValueList), cookie)
+	return ChangeKeyboardControlCookie{cookie}
+}
+
+func (cook ChangeKeyboardControlCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for ChangeKeyboardControl
-func changeKeyboardControlRequest(ValueMask uint32, ValueList []uint32) []byte {
+func (c *Conn) changeKeyboardControlRequest(ValueMask uint32, ValueList []uint32) []byte {
 	size := pad((4 + (4 + pad((4 * popCount(int(ValueMask)))))))
 	b := 0
 	buf := make([]byte, size)
@@ -12121,18 +13250,20 @@ func changeKeyboardControlRequest(ValueMask uint32, ValueList []uint32) []byte {
 
 // Request GetKeyboardControl
 // size: 4
-type GetKeyboardControlCookie cookie
+type GetKeyboardControlCookie struct {
+	*cookie
+}
 
 func (c *Conn) GetKeyboardControl() GetKeyboardControlCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(getKeyboardControlRequest(), cookie)
-	return GetKeyboardControlCookie(cookie)
+	c.newRequest(c.getKeyboardControlRequest(), cookie)
+	return GetKeyboardControlCookie{cookie}
 }
 
 func (c *Conn) GetKeyboardControlUnchecked() GetKeyboardControlCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(getKeyboardControlRequest(), cookie)
-	return GetKeyboardControlCookie(cookie)
+	c.newRequest(c.getKeyboardControlRequest(), cookie)
+	return GetKeyboardControlCookie{cookie}
 }
 
 // Request reply for GetKeyboardControl
@@ -12152,10 +13283,13 @@ type GetKeyboardControlReply struct {
 
 // Waits and reads reply data from request GetKeyboardControl
 func (cook GetKeyboardControlCookie) Reply() (*GetKeyboardControlReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return getKeyboardControlReply(buf), nil
 }
 
@@ -12197,8 +13331,12 @@ func getKeyboardControlReply(buf []byte) *GetKeyboardControlReply {
 	return v
 }
 
+func (cook GetKeyboardControlCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for GetKeyboardControl
-func getKeyboardControlRequest() []byte {
+func (c *Conn) getKeyboardControlRequest() []byte {
 	size := 4
 	b := 0
 	buf := make([]byte, size)
@@ -12206,28 +13344,38 @@ func getKeyboardControlRequest() []byte {
 	buf[b] = 103 // request opcode
 	b += 1
 
+	b += 1                         // padding
+	Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
+	b += 2
+
 	return buf
 }
 
 // Request Bell
 // size: 4
-type BellCookie cookie
+type BellCookie struct {
+	*cookie
+}
 
 // Write request to wire for Bell
 func (c *Conn) Bell(Percent int8) BellCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(bellRequest(Percent), cookie)
-	return BellCookie(cookie)
+	c.newRequest(c.bellRequest(Percent), cookie)
+	return BellCookie{cookie}
 }
 
 func (c *Conn) BellChecked(Percent int8) BellCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(bellRequest(Percent), cookie)
-	return BellCookie(cookie)
+	c.newRequest(c.bellRequest(Percent), cookie)
+	return BellCookie{cookie}
+}
+
+func (cook BellCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for Bell
-func bellRequest(Percent int8) []byte {
+func (c *Conn) bellRequest(Percent int8) []byte {
 	size := 4
 	b := 0
 	buf := make([]byte, size)
@@ -12238,28 +13386,37 @@ func bellRequest(Percent int8) []byte {
 	buf[b] = byte(Percent)
 	b += 1
 
+	Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
+	b += 2
+
 	return buf
 }
 
 // Request ChangePointerControl
 // size: 12
-type ChangePointerControlCookie cookie
+type ChangePointerControlCookie struct {
+	*cookie
+}
 
 // Write request to wire for ChangePointerControl
 func (c *Conn) ChangePointerControl(AccelerationNumerator int16, AccelerationDenominator int16, Threshold int16, DoAcceleration bool, DoThreshold bool) ChangePointerControlCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(changePointerControlRequest(AccelerationNumerator, AccelerationDenominator, Threshold, DoAcceleration, DoThreshold), cookie)
-	return ChangePointerControlCookie(cookie)
+	c.newRequest(c.changePointerControlRequest(AccelerationNumerator, AccelerationDenominator, Threshold, DoAcceleration, DoThreshold), cookie)
+	return ChangePointerControlCookie{cookie}
 }
 
 func (c *Conn) ChangePointerControlChecked(AccelerationNumerator int16, AccelerationDenominator int16, Threshold int16, DoAcceleration bool, DoThreshold bool) ChangePointerControlCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(changePointerControlRequest(AccelerationNumerator, AccelerationDenominator, Threshold, DoAcceleration, DoThreshold), cookie)
-	return ChangePointerControlCookie(cookie)
+	c.newRequest(c.changePointerControlRequest(AccelerationNumerator, AccelerationDenominator, Threshold, DoAcceleration, DoThreshold), cookie)
+	return ChangePointerControlCookie{cookie}
+}
+
+func (cook ChangePointerControlCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for ChangePointerControl
-func changePointerControlRequest(AccelerationNumerator int16, AccelerationDenominator int16, Threshold int16, DoAcceleration bool, DoThreshold bool) []byte {
+func (c *Conn) changePointerControlRequest(AccelerationNumerator int16, AccelerationDenominator int16, Threshold int16, DoAcceleration bool, DoThreshold bool) []byte {
 	size := 12
 	b := 0
 	buf := make([]byte, size)
@@ -12300,18 +13457,20 @@ func changePointerControlRequest(AccelerationNumerator int16, AccelerationDenomi
 
 // Request GetPointerControl
 // size: 4
-type GetPointerControlCookie cookie
+type GetPointerControlCookie struct {
+	*cookie
+}
 
 func (c *Conn) GetPointerControl() GetPointerControlCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(getPointerControlRequest(), cookie)
-	return GetPointerControlCookie(cookie)
+	c.newRequest(c.getPointerControlRequest(), cookie)
+	return GetPointerControlCookie{cookie}
 }
 
 func (c *Conn) GetPointerControlUnchecked() GetPointerControlCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(getPointerControlRequest(), cookie)
-	return GetPointerControlCookie(cookie)
+	c.newRequest(c.getPointerControlRequest(), cookie)
+	return GetPointerControlCookie{cookie}
 }
 
 // Request reply for GetPointerControl
@@ -12328,10 +13487,13 @@ type GetPointerControlReply struct {
 
 // Waits and reads reply data from request GetPointerControl
 func (cook GetPointerControlCookie) Reply() (*GetPointerControlReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return getPointerControlReply(buf), nil
 }
 
@@ -12362,8 +13524,12 @@ func getPointerControlReply(buf []byte) *GetPointerControlReply {
 	return v
 }
 
+func (cook GetPointerControlCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for GetPointerControl
-func getPointerControlRequest() []byte {
+func (c *Conn) getPointerControlRequest() []byte {
 	size := 4
 	b := 0
 	buf := make([]byte, size)
@@ -12371,28 +13537,38 @@ func getPointerControlRequest() []byte {
 	buf[b] = 106 // request opcode
 	b += 1
 
+	b += 1                         // padding
+	Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
+	b += 2
+
 	return buf
 }
 
 // Request SetScreenSaver
 // size: 12
-type SetScreenSaverCookie cookie
+type SetScreenSaverCookie struct {
+	*cookie
+}
 
 // Write request to wire for SetScreenSaver
 func (c *Conn) SetScreenSaver(Timeout int16, Interval int16, PreferBlanking byte, AllowExposures byte) SetScreenSaverCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(setScreenSaverRequest(Timeout, Interval, PreferBlanking, AllowExposures), cookie)
-	return SetScreenSaverCookie(cookie)
+	c.newRequest(c.setScreenSaverRequest(Timeout, Interval, PreferBlanking, AllowExposures), cookie)
+	return SetScreenSaverCookie{cookie}
 }
 
 func (c *Conn) SetScreenSaverChecked(Timeout int16, Interval int16, PreferBlanking byte, AllowExposures byte) SetScreenSaverCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(setScreenSaverRequest(Timeout, Interval, PreferBlanking, AllowExposures), cookie)
-	return SetScreenSaverCookie(cookie)
+	c.newRequest(c.setScreenSaverRequest(Timeout, Interval, PreferBlanking, AllowExposures), cookie)
+	return SetScreenSaverCookie{cookie}
+}
+
+func (cook SetScreenSaverCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for SetScreenSaver
-func setScreenSaverRequest(Timeout int16, Interval int16, PreferBlanking byte, AllowExposures byte) []byte {
+func (c *Conn) setScreenSaverRequest(Timeout int16, Interval int16, PreferBlanking byte, AllowExposures byte) []byte {
 	size := 12
 	b := 0
 	buf := make([]byte, size)
@@ -12422,18 +13598,20 @@ func setScreenSaverRequest(Timeout int16, Interval int16, PreferBlanking byte, A
 
 // Request GetScreenSaver
 // size: 4
-type GetScreenSaverCookie cookie
+type GetScreenSaverCookie struct {
+	*cookie
+}
 
 func (c *Conn) GetScreenSaver() GetScreenSaverCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(getScreenSaverRequest(), cookie)
-	return GetScreenSaverCookie(cookie)
+	c.newRequest(c.getScreenSaverRequest(), cookie)
+	return GetScreenSaverCookie{cookie}
 }
 
 func (c *Conn) GetScreenSaverUnchecked() GetScreenSaverCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(getScreenSaverRequest(), cookie)
-	return GetScreenSaverCookie(cookie)
+	c.newRequest(c.getScreenSaverRequest(), cookie)
+	return GetScreenSaverCookie{cookie}
 }
 
 // Request reply for GetScreenSaver
@@ -12451,10 +13629,13 @@ type GetScreenSaverReply struct {
 
 // Waits and reads reply data from request GetScreenSaver
 func (cook GetScreenSaverCookie) Reply() (*GetScreenSaverReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return getScreenSaverReply(buf), nil
 }
 
@@ -12488,8 +13669,12 @@ func getScreenSaverReply(buf []byte) *GetScreenSaverReply {
 	return v
 }
 
+func (cook GetScreenSaverCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for GetScreenSaver
-func getScreenSaverRequest() []byte {
+func (c *Conn) getScreenSaverRequest() []byte {
 	size := 4
 	b := 0
 	buf := make([]byte, size)
@@ -12497,28 +13682,38 @@ func getScreenSaverRequest() []byte {
 	buf[b] = 108 // request opcode
 	b += 1
 
+	b += 1                         // padding
+	Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
+	b += 2
+
 	return buf
 }
 
 // Request ChangeHosts
 // size: pad((8 + pad((int(AddressLen) * 1))))
-type ChangeHostsCookie cookie
+type ChangeHostsCookie struct {
+	*cookie
+}
 
 // Write request to wire for ChangeHosts
 func (c *Conn) ChangeHosts(Mode byte, Family byte, AddressLen uint16, Address []byte) ChangeHostsCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(changeHostsRequest(Mode, Family, AddressLen, Address), cookie)
-	return ChangeHostsCookie(cookie)
+	c.newRequest(c.changeHostsRequest(Mode, Family, AddressLen, Address), cookie)
+	return ChangeHostsCookie{cookie}
 }
 
 func (c *Conn) ChangeHostsChecked(Mode byte, Family byte, AddressLen uint16, Address []byte) ChangeHostsCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(changeHostsRequest(Mode, Family, AddressLen, Address), cookie)
-	return ChangeHostsCookie(cookie)
+	c.newRequest(c.changeHostsRequest(Mode, Family, AddressLen, Address), cookie)
+	return ChangeHostsCookie{cookie}
+}
+
+func (cook ChangeHostsCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for ChangeHosts
-func changeHostsRequest(Mode byte, Family byte, AddressLen uint16, Address []byte) []byte {
+func (c *Conn) changeHostsRequest(Mode byte, Family byte, AddressLen uint16, Address []byte) []byte {
 	size := pad((8 + pad((int(AddressLen) * 1))))
 	b := 0
 	buf := make([]byte, size)
@@ -12548,18 +13743,20 @@ func changeHostsRequest(Mode byte, Family byte, AddressLen uint16, Address []byt
 
 // Request ListHosts
 // size: 4
-type ListHostsCookie cookie
+type ListHostsCookie struct {
+	*cookie
+}
 
 func (c *Conn) ListHosts() ListHostsCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(listHostsRequest(), cookie)
-	return ListHostsCookie(cookie)
+	c.newRequest(c.listHostsRequest(), cookie)
+	return ListHostsCookie{cookie}
 }
 
 func (c *Conn) ListHostsUnchecked() ListHostsCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(listHostsRequest(), cookie)
-	return ListHostsCookie(cookie)
+	c.newRequest(c.listHostsRequest(), cookie)
+	return ListHostsCookie{cookie}
 }
 
 // Request reply for ListHosts
@@ -12575,10 +13772,13 @@ type ListHostsReply struct {
 
 // Waits and reads reply data from request ListHosts
 func (cook ListHostsCookie) Reply() (*ListHostsReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return listHostsReply(buf), nil
 }
 
@@ -12607,8 +13807,12 @@ func listHostsReply(buf []byte) *ListHostsReply {
 	return v
 }
 
+func (cook ListHostsCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for ListHosts
-func listHostsRequest() []byte {
+func (c *Conn) listHostsRequest() []byte {
 	size := 4
 	b := 0
 	buf := make([]byte, size)
@@ -12616,28 +13820,38 @@ func listHostsRequest() []byte {
 	buf[b] = 110 // request opcode
 	b += 1
 
+	b += 1                         // padding
+	Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
+	b += 2
+
 	return buf
 }
 
 // Request SetAccessControl
 // size: 4
-type SetAccessControlCookie cookie
+type SetAccessControlCookie struct {
+	*cookie
+}
 
 // Write request to wire for SetAccessControl
 func (c *Conn) SetAccessControl(Mode byte) SetAccessControlCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(setAccessControlRequest(Mode), cookie)
-	return SetAccessControlCookie(cookie)
+	c.newRequest(c.setAccessControlRequest(Mode), cookie)
+	return SetAccessControlCookie{cookie}
 }
 
 func (c *Conn) SetAccessControlChecked(Mode byte) SetAccessControlCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(setAccessControlRequest(Mode), cookie)
-	return SetAccessControlCookie(cookie)
+	c.newRequest(c.setAccessControlRequest(Mode), cookie)
+	return SetAccessControlCookie{cookie}
+}
+
+func (cook SetAccessControlCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for SetAccessControl
-func setAccessControlRequest(Mode byte) []byte {
+func (c *Conn) setAccessControlRequest(Mode byte) []byte {
 	size := 4
 	b := 0
 	buf := make([]byte, size)
@@ -12648,28 +13862,37 @@ func setAccessControlRequest(Mode byte) []byte {
 	buf[b] = Mode
 	b += 1
 
+	Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
+	b += 2
+
 	return buf
 }
 
 // Request SetCloseDownMode
 // size: 4
-type SetCloseDownModeCookie cookie
+type SetCloseDownModeCookie struct {
+	*cookie
+}
 
 // Write request to wire for SetCloseDownMode
 func (c *Conn) SetCloseDownMode(Mode byte) SetCloseDownModeCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(setCloseDownModeRequest(Mode), cookie)
-	return SetCloseDownModeCookie(cookie)
+	c.newRequest(c.setCloseDownModeRequest(Mode), cookie)
+	return SetCloseDownModeCookie{cookie}
 }
 
 func (c *Conn) SetCloseDownModeChecked(Mode byte) SetCloseDownModeCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(setCloseDownModeRequest(Mode), cookie)
-	return SetCloseDownModeCookie(cookie)
+	c.newRequest(c.setCloseDownModeRequest(Mode), cookie)
+	return SetCloseDownModeCookie{cookie}
+}
+
+func (cook SetCloseDownModeCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for SetCloseDownMode
-func setCloseDownModeRequest(Mode byte) []byte {
+func (c *Conn) setCloseDownModeRequest(Mode byte) []byte {
 	size := 4
 	b := 0
 	buf := make([]byte, size)
@@ -12680,28 +13903,37 @@ func setCloseDownModeRequest(Mode byte) []byte {
 	buf[b] = Mode
 	b += 1
 
+	Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
+	b += 2
+
 	return buf
 }
 
 // Request KillClient
 // size: 8
-type KillClientCookie cookie
+type KillClientCookie struct {
+	*cookie
+}
 
 // Write request to wire for KillClient
 func (c *Conn) KillClient(Resource uint32) KillClientCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(killClientRequest(Resource), cookie)
-	return KillClientCookie(cookie)
+	c.newRequest(c.killClientRequest(Resource), cookie)
+	return KillClientCookie{cookie}
 }
 
 func (c *Conn) KillClientChecked(Resource uint32) KillClientCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(killClientRequest(Resource), cookie)
-	return KillClientCookie(cookie)
+	c.newRequest(c.killClientRequest(Resource), cookie)
+	return KillClientCookie{cookie}
+}
+
+func (cook KillClientCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for KillClient
-func killClientRequest(Resource uint32) []byte {
+func (c *Conn) killClientRequest(Resource uint32) []byte {
 	size := 8
 	b := 0
 	buf := make([]byte, size)
@@ -12722,23 +13954,29 @@ func killClientRequest(Resource uint32) []byte {
 
 // Request RotateProperties
 // size: pad((12 + pad((int(AtomsLen) * 4))))
-type RotatePropertiesCookie cookie
+type RotatePropertiesCookie struct {
+	*cookie
+}
 
 // Write request to wire for RotateProperties
 func (c *Conn) RotateProperties(Window Id, AtomsLen uint16, Delta int16, Atoms []Id) RotatePropertiesCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(rotatePropertiesRequest(Window, AtomsLen, Delta, Atoms), cookie)
-	return RotatePropertiesCookie(cookie)
+	c.newRequest(c.rotatePropertiesRequest(Window, AtomsLen, Delta, Atoms), cookie)
+	return RotatePropertiesCookie{cookie}
 }
 
 func (c *Conn) RotatePropertiesChecked(Window Id, AtomsLen uint16, Delta int16, Atoms []Id) RotatePropertiesCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(rotatePropertiesRequest(Window, AtomsLen, Delta, Atoms), cookie)
-	return RotatePropertiesCookie(cookie)
+	c.newRequest(c.rotatePropertiesRequest(Window, AtomsLen, Delta, Atoms), cookie)
+	return RotatePropertiesCookie{cookie}
+}
+
+func (cook RotatePropertiesCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for RotateProperties
-func rotatePropertiesRequest(Window Id, AtomsLen uint16, Delta int16, Atoms []Id) []byte {
+func (c *Conn) rotatePropertiesRequest(Window Id, AtomsLen uint16, Delta int16, Atoms []Id) []byte {
 	size := pad((12 + pad((int(AtomsLen) * 4))))
 	b := 0
 	buf := make([]byte, size)
@@ -12771,23 +14009,29 @@ func rotatePropertiesRequest(Window Id, AtomsLen uint16, Delta int16, Atoms []Id
 
 // Request ForceScreenSaver
 // size: 4
-type ForceScreenSaverCookie cookie
+type ForceScreenSaverCookie struct {
+	*cookie
+}
 
 // Write request to wire for ForceScreenSaver
 func (c *Conn) ForceScreenSaver(Mode byte) ForceScreenSaverCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(forceScreenSaverRequest(Mode), cookie)
-	return ForceScreenSaverCookie(cookie)
+	c.newRequest(c.forceScreenSaverRequest(Mode), cookie)
+	return ForceScreenSaverCookie{cookie}
 }
 
 func (c *Conn) ForceScreenSaverChecked(Mode byte) ForceScreenSaverCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(forceScreenSaverRequest(Mode), cookie)
-	return ForceScreenSaverCookie(cookie)
+	c.newRequest(c.forceScreenSaverRequest(Mode), cookie)
+	return ForceScreenSaverCookie{cookie}
+}
+
+func (cook ForceScreenSaverCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for ForceScreenSaver
-func forceScreenSaverRequest(Mode byte) []byte {
+func (c *Conn) forceScreenSaverRequest(Mode byte) []byte {
 	size := 4
 	b := 0
 	buf := make([]byte, size)
@@ -12798,23 +14042,28 @@ func forceScreenSaverRequest(Mode byte) []byte {
 	buf[b] = Mode
 	b += 1
 
+	Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
+	b += 2
+
 	return buf
 }
 
 // Request SetPointerMapping
 // size: pad((4 + pad((int(MapLen) * 1))))
-type SetPointerMappingCookie cookie
+type SetPointerMappingCookie struct {
+	*cookie
+}
 
 func (c *Conn) SetPointerMapping(MapLen byte, Map []byte) SetPointerMappingCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(setPointerMappingRequest(MapLen, Map), cookie)
-	return SetPointerMappingCookie(cookie)
+	c.newRequest(c.setPointerMappingRequest(MapLen, Map), cookie)
+	return SetPointerMappingCookie{cookie}
 }
 
 func (c *Conn) SetPointerMappingUnchecked(MapLen byte, Map []byte) SetPointerMappingCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(setPointerMappingRequest(MapLen, Map), cookie)
-	return SetPointerMappingCookie(cookie)
+	c.newRequest(c.setPointerMappingRequest(MapLen, Map), cookie)
+	return SetPointerMappingCookie{cookie}
 }
 
 // Request reply for SetPointerMapping
@@ -12827,10 +14076,13 @@ type SetPointerMappingReply struct {
 
 // Waits and reads reply data from request SetPointerMapping
 func (cook SetPointerMappingCookie) Reply() (*SetPointerMappingReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return setPointerMappingReply(buf), nil
 }
 
@@ -12842,11 +14094,21 @@ func setPointerMappingReply(buf []byte) *SetPointerMappingReply {
 	v.Status = buf[b]
 	b += 1
 
+	v.Sequence = Get16(buf[b:])
+	b += 2
+
+	v.Length = Get32(buf[b:]) // 4-byte units
+	b += 4
+
 	return v
 }
 
+func (cook SetPointerMappingCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for SetPointerMapping
-func setPointerMappingRequest(MapLen byte, Map []byte) []byte {
+func (c *Conn) setPointerMappingRequest(MapLen byte, Map []byte) []byte {
 	size := pad((4 + pad((int(MapLen) * 1))))
 	b := 0
 	buf := make([]byte, size)
@@ -12868,18 +14130,20 @@ func setPointerMappingRequest(MapLen byte, Map []byte) []byte {
 
 // Request GetPointerMapping
 // size: 4
-type GetPointerMappingCookie cookie
+type GetPointerMappingCookie struct {
+	*cookie
+}
 
 func (c *Conn) GetPointerMapping() GetPointerMappingCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(getPointerMappingRequest(), cookie)
-	return GetPointerMappingCookie(cookie)
+	c.newRequest(c.getPointerMappingRequest(), cookie)
+	return GetPointerMappingCookie{cookie}
 }
 
 func (c *Conn) GetPointerMappingUnchecked() GetPointerMappingCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(getPointerMappingRequest(), cookie)
-	return GetPointerMappingCookie(cookie)
+	c.newRequest(c.getPointerMappingRequest(), cookie)
+	return GetPointerMappingCookie{cookie}
 }
 
 // Request reply for GetPointerMapping
@@ -12894,10 +14158,13 @@ type GetPointerMappingReply struct {
 
 // Waits and reads reply data from request GetPointerMapping
 func (cook GetPointerMappingCookie) Reply() (*GetPointerMappingReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return getPointerMappingReply(buf), nil
 }
 
@@ -12924,8 +14191,12 @@ func getPointerMappingReply(buf []byte) *GetPointerMappingReply {
 	return v
 }
 
+func (cook GetPointerMappingCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for GetPointerMapping
-func getPointerMappingRequest() []byte {
+func (c *Conn) getPointerMappingRequest() []byte {
 	size := 4
 	b := 0
 	buf := make([]byte, size)
@@ -12933,23 +14204,29 @@ func getPointerMappingRequest() []byte {
 	buf[b] = 117 // request opcode
 	b += 1
 
+	b += 1                         // padding
+	Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
+	b += 2
+
 	return buf
 }
 
 // Request SetModifierMapping
 // size: pad((4 + pad(((int(KeycodesPerModifier) * 8) * 1))))
-type SetModifierMappingCookie cookie
+type SetModifierMappingCookie struct {
+	*cookie
+}
 
 func (c *Conn) SetModifierMapping(KeycodesPerModifier byte, Keycodes []Keycode) SetModifierMappingCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(setModifierMappingRequest(KeycodesPerModifier, Keycodes), cookie)
-	return SetModifierMappingCookie(cookie)
+	c.newRequest(c.setModifierMappingRequest(KeycodesPerModifier, Keycodes), cookie)
+	return SetModifierMappingCookie{cookie}
 }
 
 func (c *Conn) SetModifierMappingUnchecked(KeycodesPerModifier byte, Keycodes []Keycode) SetModifierMappingCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(setModifierMappingRequest(KeycodesPerModifier, Keycodes), cookie)
-	return SetModifierMappingCookie(cookie)
+	c.newRequest(c.setModifierMappingRequest(KeycodesPerModifier, Keycodes), cookie)
+	return SetModifierMappingCookie{cookie}
 }
 
 // Request reply for SetModifierMapping
@@ -12962,10 +14239,13 @@ type SetModifierMappingReply struct {
 
 // Waits and reads reply data from request SetModifierMapping
 func (cook SetModifierMappingCookie) Reply() (*SetModifierMappingReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return setModifierMappingReply(buf), nil
 }
 
@@ -12977,11 +14257,21 @@ func setModifierMappingReply(buf []byte) *SetModifierMappingReply {
 	v.Status = buf[b]
 	b += 1
 
+	v.Sequence = Get16(buf[b:])
+	b += 2
+
+	v.Length = Get32(buf[b:]) // 4-byte units
+	b += 4
+
 	return v
 }
 
+func (cook SetModifierMappingCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for SetModifierMapping
-func setModifierMappingRequest(KeycodesPerModifier byte, Keycodes []Keycode) []byte {
+func (c *Conn) setModifierMappingRequest(KeycodesPerModifier byte, Keycodes []Keycode) []byte {
 	size := pad((4 + pad(((int(KeycodesPerModifier) * 8) * 1))))
 	b := 0
 	buf := make([]byte, size)
@@ -13006,18 +14296,20 @@ func setModifierMappingRequest(KeycodesPerModifier byte, Keycodes []Keycode) []b
 
 // Request GetModifierMapping
 // size: 4
-type GetModifierMappingCookie cookie
+type GetModifierMappingCookie struct {
+	*cookie
+}
 
 func (c *Conn) GetModifierMapping() GetModifierMappingCookie {
 	cookie := c.newCookie(true, true)
-	c.newRequest(getModifierMappingRequest(), cookie)
-	return GetModifierMappingCookie(cookie)
+	c.newRequest(c.getModifierMappingRequest(), cookie)
+	return GetModifierMappingCookie{cookie}
 }
 
 func (c *Conn) GetModifierMappingUnchecked() GetModifierMappingCookie {
 	cookie := c.newCookie(false, true)
-	c.newRequest(getModifierMappingRequest(), cookie)
-	return GetModifierMappingCookie(cookie)
+	c.newRequest(c.getModifierMappingRequest(), cookie)
+	return GetModifierMappingCookie{cookie}
 }
 
 // Request reply for GetModifierMapping
@@ -13032,10 +14324,13 @@ type GetModifierMappingReply struct {
 
 // Waits and reads reply data from request GetModifierMapping
 func (cook GetModifierMappingCookie) Reply() (*GetModifierMappingReply, error) {
-	buf, err := cookie(cook).reply()
+	buf, err := cook.reply()
 	if err != nil {
 		return nil, err
 	}
+	if buf == nil {
+		return nil, nil
+	}
 	return getModifierMappingReply(buf), nil
 }
 
@@ -13065,8 +14360,12 @@ func getModifierMappingReply(buf []byte) *GetModifierMappingReply {
 	return v
 }
 
+func (cook GetModifierMappingCookie) Check() error {
+	return cook.check()
+}
+
 // Write request to wire for GetModifierMapping
-func getModifierMappingRequest() []byte {
+func (c *Conn) getModifierMappingRequest() []byte {
 	size := 4
 	b := 0
 	buf := make([]byte, size)
@@ -13074,28 +14373,38 @@ func getModifierMappingRequest() []byte {
 	buf[b] = 119 // request opcode
 	b += 1
 
+	b += 1                         // padding
+	Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
+	b += 2
+
 	return buf
 }
 
 // Request NoOperation
 // size: 4
-type NoOperationCookie cookie
+type NoOperationCookie struct {
+	*cookie
+}
 
 // Write request to wire for NoOperation
 func (c *Conn) NoOperation() NoOperationCookie {
 	cookie := c.newCookie(false, false)
-	c.newRequest(noOperationRequest(), cookie)
-	return NoOperationCookie(cookie)
+	c.newRequest(c.noOperationRequest(), cookie)
+	return NoOperationCookie{cookie}
 }
 
 func (c *Conn) NoOperationChecked() NoOperationCookie {
 	cookie := c.newCookie(true, false)
-	c.newRequest(noOperationRequest(), cookie)
-	return NoOperationCookie(cookie)
+	c.newRequest(c.noOperationRequest(), cookie)
+	return NoOperationCookie{cookie}
+}
+
+func (cook NoOperationCookie) Check() error {
+	return cook.check()
 }
 
 // Write request to wire for NoOperation
-func noOperationRequest() []byte {
+func (c *Conn) noOperationRequest() []byte {
 	size := 4
 	b := 0
 	buf := make([]byte, size)
@@ -13103,5 +14412,9 @@ func noOperationRequest() []byte {
 	buf[b] = 127 // request opcode
 	b += 1
 
+	b += 1                         // padding
+	Put16(buf[b:], uint16(size/4)) // write request size in 4-byte units
+	b += 2
+
 	return buf
 }