code: def addToProcessedTxns(self,
                             identifier: str,
                             txnId: str,
                             reply: Reply) -> None:
          
          self.transactions[txnId] = reply
          if identifier not in self.processedRequests:
              self.processedRequests[identifier] = {}
          self.processedRequests[identifier][reply.reqId] = txnId
docs: Add a client request to the transaction store's list of processed
          requests.