code: def _split_message(self, message):
          
          if len(message) == 3:
              return message
          else:
              # get_more and kill_cursors messages don't include BSON documents.
              request_id, data = message
              return request_id, data, 0
docs: Return request_id, data, max_doc_size.
  
          :Parameters:
            - `message`: (request_id, data, max_doc_size) or (request_id, data)