gtk/gtk.go
func (v *ToolItem) SetProxyMenuItem(menuItemId string, menuItem IMenuItem) {
	cstr := C.CString(menuItemId)
	defer C.free(unsafe.Pointer(cstr))
	C.gtk_tool_item_set_proxy_menu_item(v.native(), (*C.gchar)(cstr),
		C.toGtkWidget(unsafe.Pointer(menuItem.toMenuItem())))
}
func (v *ToolItem) SetProxyMenuItem(menuItemId string, menuItem IMenuItem) {
	cstr := C.CString(menuItemId)
	defer C.free(unsafe.Pointer(cstr))
	C.gtk_tool_item_set_proxy_menu_item(v.native(), (*C.gchar)(cstr),
		C.toGtkWidget(unsafe.Pointer(menuItem.toMenuItem())))
}
// SetProxyMenuItem is a wrapper around gtk_tool_item_set_proxy_menu_item().