code: def reply_to_request(self, req, rep):
          
  
          assert isinstance(req, EventRequestBase)
          assert isinstance(rep, EventReplyBase)
          rep.dst = req.src
          if req.sync:
              req.reply_q.put(rep)
          else:
              self.send_event(rep.dst, rep)
docs: Send a reply for a synchronous request sent by send_request.
          The first argument should be an instance of EventRequestBase.
          The second argument should be an instance of EventReplyBase.