/**
  * get last notification for a give user id
  * @param  int   $userId [description]
  * @return array | null
  */
 protected function getLastNotification($userId)
 {
     $rez = null;
     //save current user id
     $currentUser = $_SESSION['user']['id'];
     $api = new \CB\Api\Notifications();
     $result = $api->getList(array('limit' => 900));
     if ($result['success'] == true && !empty($result['data'])) {
         $rez = array_shift($result['data']);
     }
     //restore previous user id
     $_SESSION['user']['id'] = $currentUser;
     return $rez;
 }