/**
  * Get instance for extension
  * @param Extension_Extension $extension
  * @return IWidget
  */
 public static function GetByExtension(Extension_Extension $extension)
 {
     global $g_user;
     // be able to render
     $widget = new WidgetRendererDecorator(array('fk_user_id' => $g_user->getId(), 'fk_widget_id' => $extension->getId()));
     // set extension, widget
     $widget->extension = $extension;
     $widget->setWidget($extension->getInstance());
     return $widget;
 }