code: def download_dataset(self, dataset_key):
          
          owner_id, dataset_id = parse_dataset_key(dataset_key)
          try:
              return self._download_api.download_dataset(owner_id, dataset_id)
          except _swagger.rest.ApiException as e:
              raise RestApiError(cause=e)
docs: Return a .zip containing all files within the dataset as uploaded.
  
          :param dataset_key : Dataset identifier, in the form of owner/id
          :type dataset_key: str
          :returns: .zip file contain files within dataset
          :rtype: file object
          :raises RestApiException: If a server error occurs
  
          Examples
          --------
          >>> import datadotworld as dw
          >>> api_client = dw.api_client()
          >>> api_client.download_dataset(
          ...     'username/test-dataset')  # doctest: +SKIP