/**
  * Return user's memberships as array
  * 
  * @param integer $user_id user identifier
  * @return array
  */
 public function getUserMemberships($user_id)
 {
     if (empty($user_id)) {
         throw new \Exception('Empty user id');
     }
     parent::setFormatSettings('get_services', true);
     $memberships = $this->formatMemberships($this->getUserMembershipsList(null, array('where' => array('id_user' => $user_id))));
     parent::setFormatSettings('get_services', true);
     return $memberships;
 }