code: func (v *Dialog) GetWidgetForResponse(id ResponseType) (*Widget, error) {
  	c := C.gtk_dialog_get_widget_for_response(v.native(), C.gint(id))
  	if c == nil {
  		return nil, nilPtrErr
  	}
  	obj := glib.Take(unsafe.Pointer(c))
  	return wrapWidget(obj), nil
  }
docs: // GetWidgetForResponse() is a wrapper around
  // gtk_dialog_get_widget_for_response().