code: def _deliverAnswer(self, answer):
          
          router = self.siteRouter
          if answer.deliveryDeferred is None:
              d = answer.deliveryDeferred = router.routeAnswer(
                  answer.originalSender, answer.originalTarget, answer.value,
                  answer.messageID)
              def destroyAnswer(result):
                  answer.deleteFromStore()
              def transportErrorCheck(f):
                  answer.deliveryDeferred = None
                  f.trap(MessageTransportError)
              d.addCallbacks(destroyAnswer, transportErrorCheck)
              d.addErrback(log.err)
docs: Attempt to deliver an answer to a message sent to this store, via my
          store's parent's L{IMessageRouter} powerup.
  
          @param answer: an L{AlreadyAnswered} that contains an answer to a
          message sent to this store.