code: def _get_content_body(self, message_uuid, body_size):
          
          body = bytes()
          while len(body) < body_size:
              body_piece = self._channel.rpc.get_request(message_uuid, raw=True,
                                                         multiple=True)
              if not body_piece.value:
                  break
              body += body_piece.value
          return body
docs: Get Content Body using RPC requests.
  
          :param str uuid_body: Rpc Identifier.
          :param int body_size: Content Size.
  
          :rtype: str