code: func (v *Menu) PopupAtPointer(triggerEvent *gdk.Event) {
  	e := (*C.GdkEvent)(unsafe.Pointer(triggerEvent.Native()))
  	C.gtk_menu_popup_at_pointer(v.native(), e)
  }
docs: // PopupAtPointer() is a wrapper for gtk_menu_popup_at_pointer(), on older versions it uses PopupAtMouseCursor