public static function initialize($str)
 {
     $idHandler = new self();
     if (self::isSerialized($str)) {
         $object = json_decode($str);
         if (isset($object->video)) {
             $idHandler->setVideoId($object->video);
         }
         if (isset($object->asset)) {
             $idHandler->setAssetId($object->asset);
         }
         if (isset($object->reference)) {
             $idHandler->setReferenceId($object->reference);
         }
     } else {
         $idHandler->setVideoId($str);
     }
     return $idHandler;
 }