public function actionMassDelete()
    {
        if (($ids = Yii::$app->request->post('ids')) !== null) {
            $models = $this->findUser($ids);
            foreach ($models as $model) {
                $model->delete($model);
            }
            return $this->redirect(['index']);
        } else {
            throw new HttpException(400);
        }
    }