code: def get_or_none(cls, video_id, language_code):
          
          try:
              transcript = cls.objects.get(video__edx_video_id=video_id, language_code=language_code)
          except cls.DoesNotExist:
              transcript = None
  
          return transcript
docs: Returns a data model object if found or none otherwise.
  
          Arguments:
              video_id(unicode): video id to which transcript may be associated
              language_code(unicode): language of the requested transcript