code: func (v *Widget) GetParentWindow() (*gdk.Window, error) {
  	c := C.gtk_widget_get_parent_window(v.native())
  	if v == nil {
  		return nil, nilPtrErr
  	}
  
  	w := &gdk.Window{glib.Take(unsafe.Pointer(c))}
  	return w, nil
  }
docs: // GetParentWindow is a wrapper around gtk_widget_get_parent_window().