protected function removeUser(Request $request)
 {
     $userId = $request->request->get('userId');
     if (!empty($userId)) {
         if (User::deleteByUserId($userId)) {
             UserRole::deleteByUserId($userId);
             Sharing::deleteByUserId($userId);
             return $this->success();
         }
     }
     $this->abort(500, 'error.cannotRemoveUser');
 }