/**
  * Function return array of MessageModel
  * @return array
  */
 public function getMessages()
 {
     $params = ['owner' => $this->credentials, 'maxLimit' => $this->maxLimit];
     $result = $this->_client->getMessages($params);
     return isset($result->return) ? FactoryMessage::getMessages($result->return) : null;
 }