/**
  * Needs the DataListExtension from ntb/silverstripe-rest-api.
  *
  * @param string $url the url slug
  * @return DataObject the data object with the given url slug
  */
 public function byURL($url)
 {
     return $this->cache($url, function () use($url) {
         return parent::byURL($url);
     });
 }