/**
  * Return ModelInterface
  *
  * @param
  *            int|null Id of resource to get
  * @return ModelInterface
  */
 protected function _get($id = null)
 {
     $api = $this;
     $this->api->setApi('get', function ($params) use($api) {
         $url = $api->getUrl();
         if (isset($params[0])) {
             $url .= '/' . $params[0];
         }
         return array('url' => $url, 'header' => array('Content-Type' => 'application/json'), 'method' => 'GET', 'response' => array('format' => 'json', 'valid_codes' => array(200, 203)));
     });
     if ($result = $this->api->get($id)) {
         $resultSet = clone $this->getResultSetPrototype();
         $resultSet->initialize($result['Data']);
         return $resultSet->current();
     }
     return $result;
 }