code: def reply(self, reply, orig_req):
          
          assert (reply.mtype == Message.REPLY)
          assert reply.name == orig_req.name
          reply.mid = orig_req.mid
          return self._send_message(reply)
docs: Send an asynchronous reply to an earlier request.
  
          Parameters
          ----------
          reply : Message object
              The reply message to send.
          orig_req : Message object
              The request message being replied to. The reply message's
              id is overridden with the id from orig_req before the
              reply is sent.