docs: def post(self, request):
          """
          Creates a video transcript instance with the given information.
  
          Arguments:
              request: A WSGI request.
          """
          attrs = ('video_id', 'name', 'language_code', 'provider', 'file_format')
          missing = [attr for attr in attrs if attr not in request.data]
          if missing:
              LOGGER.warn(
                  '[VAL] Required transcript params are missing. %s', ' and '.join(missing)
              )
              return Response(
                  status=status.HTTP_400_BAD_REQUEST,
                  data=dict(message=u'{missing} must be specified.'.format(missing=' and '.join(missing)))
              )
  
          video_id = request.data['video_id']
          language_code = request.data['language_code']
          transcript_name = request.data['name']
          provider = request.data['provider']
          file_format = request.data['file_format']
  
          supported_formats = sorted(dict(TranscriptFormat.CHOICES).keys())
          if file_format not in supported_formats:
              message = (
                  u'"{format}" transcript file type is not supported. Supported formats are "{supported_formats}"'
              ).format(format=file_format, supported_formats=supported_formats)
              return Response(status=status.HTTP_400_BAD_REQUEST, data={'message': message})
  
          supported_providers = sorted(dict(TranscriptProviderType.CHOICES).keys())
          if provider not in supported_providers:
              message = (
                  u'"{provider}" provider is not supported. Supported transcription providers are "{supported_providers}"'
              ).format(provider=provider, supported_providers=supported_providers)
              return Response(status=status.HTTP_400_BAD_REQUEST, data={'message': message})
  
          transcript = VideoTranscript.get_or_none(video_id, language_code)
          if transcript is None:
              create_or_update_video_transcript(video_id, language_code, metadata={
                  'provider': provider,
                  'file_name': transcript_name,
                  'file_format': file_format
              })
              response = Response(status=status.HTTP_200_OK)
          else:
              message = (
                  u'Can not override existing transcript for video "{video_id}" and language code "{language}".'
              ).format(video_id=video_id, language=language_code)
              response = Response(status=status.HTTP_400_BAD_REQUEST, data={'message': message})
  
          return response