/**
  * get_transcript
  *
  * @param mixed $slide_key
  */
 public function get_transcript($slide_key)
 {
     App::uses('CommonHelper', 'View/Helper');
     $helper = new CommonHelper(new View());
     $url = $helper->transcript_url($slide_key);
     $contents = $this->get_contents($url);
     $transcripts = unserialize($contents);
     return $transcripts;
 }