code: func (t *UDPv4) handleReply(from enode.ID, fromIP net.IP, ptype byte, req packetV4) bool {
  	matched := make(chan bool, 1)
  	select {
  	case t.gotreply <- reply{from, fromIP, ptype, req, matched}:
  		// loop will handle it
  		return <-matched
  	case <-t.closing:
  		return false
  	}
  }
docs: // handleReply dispatches a reply packet, invoking reply matchers. It returns
  // whether any matcher considered the packet acceptable.