code: func (a *ActionBar) GetCenterWidget() *Widget {
  	w := C.gtk_action_bar_get_center_widget(a.native())
  	if w == nil {
  		return nil
  	}
  	return &Widget{glib.InitiallyUnowned{glib.Take(unsafe.Pointer(w))}}
  }
docs: //gtk_action_bar_get_center_widget(GtkActionBar *action_bar)