private function verifyId()
 {
     $this->feed = file_get_contents($this->xml);
     $xml = XMLLoader::loadString($this->feed);
     foreach ($xml->children() as $video) {
         if ($video->id == '') {
             throw new VideoNotExistsException();
         }
     }
 }
 protected function getVideoDetails()
 {
     $unserialized = Serializer::unserialize($this->video->getFeed());
     return XMLLoader::loadString($unserialized);
 }