public function actionGroup()
 {
     if (!Yii::$app->user->can('app.forum.setting.group')) {
         throw new ForbiddenHttpException(YBoard::t('yboard', 'You have no enough permission to access this page! If you think its a mistake, please consider reporting to us.'));
     }
     $model = new YBoardMembergroup(['scenario' => 'search']);
     $model->setAttributes([]);
     // clear any default values
     $model->load(Yii::$app->request->post());
     return $this->render('group', ['model' => $model]);
 }