code: async def append(self, reply: Reply) \
              -> None:
          
          result = reply.result
          identifier = result.get(f.IDENTIFIER.nm)
          txnId = result.get(TXN_ID)
          logger.debug("Reply being sent {}".format(reply))
          if self._isNewTxn(identifier, reply, txnId):
              self.addToProcessedTxns(identifier, txnId, reply)
          if identifier not in self.responses:
              self.responses[identifier] = asyncio.Queue()
          await self.responses[identifier].put(reply)
docs: Add the given Reply to this transaction store's list of responses.
          Also add to processedRequests if not added previously.