code: def routeAnswer(self, originalSender, originalTarget, value, messageID):
          
          def txn():
              qm = self._messageFromSender(originalSender, messageID)
              if qm is None:
                  return
              c = qm.consequence
              if c is not None:
                  c.answerReceived(value, qm.value,
                                   qm.sender, qm.target)
              elif value.type == DELIVERY_ERROR:
                  try:
                      raise MessageTransportError(value.data)
                  except MessageTransportError:
                      log.err(Failure(),
                              "An unhandled delivery error occurred on a message"
                              " with no consequence.")
              qm.deleteFromStore()
          try:
              self.store.transact(txn)
          except:
              log.err(Failure(),
                      "An unhandled error occurred while handling a response to "
                      "an inter-store message.")
              def answerProcessingFailure():
                  qm = self._messageFromSender(originalSender, messageID)
                  _FailedAnswer.create(store=qm.store,
                                       consequence=qm.consequence,
                                       sender=originalSender,
                                       target=originalTarget,
                                       messageValue=qm.value,
                                       answerValue=value)
                  qm.deleteFromStore()
              self.store.transact(answerProcessingFailure)
          return defer.succeed(None)
docs: Route an incoming answer to a message originally sent by this queue.