code: def _send_block_request(self, transaction):
          
          transaction = self._messageLayer.send_request(transaction.request)
          # ... but don't forget to reset the acknowledge flag
          transaction.request.acknowledged = False
          self.send_datagram(transaction.request)
          if transaction.request.type == defines.Types["CON"]:
              self._start_retransmission(transaction, transaction.request)
docs: A former request resulted in a block wise transfer. With this method, the block wise transfer
          will be continued, including triggering of the retry mechanism.
          
          :param transaction: The former transaction including the request which should be continued.