func GetCaller(ctx context.Context) *RemoteClient {
	val, _ := ctx.Value(ctxCallerKey{}).(*RemoteClient)
	return val
}

// GetSubroute returns caller information from contexts provided to handlers.
func GetSubroute(ctx context.Context) string {
	//nolint:staticcheck // SA1029 Staticcheck is drunk.
	val, _ := ctx.Value(ctxSubrouteKey{}).(string)
	return val
}

	// 1: Echo
	register := func(manager *Manager) {
		errFatal(handler.Register(manager, func(ctx context.Context, pp *testRequest, in <-chan *testRequest, out chan<- *testResponse) *RemoteErr {
			sub := GetSubroute(ctx)
			if sub != "subroute/1" {
				t.Fatal("expected subroute/1, got", sub)
			}
			n := 0
			for i := range in {
				if n > payloads {
					panic("too many requests")
				}

}

func newMuxStream(ctx context.Context, msg message, c *Connection, handler StreamHandler) *muxServer {
	var cancel context.CancelFunc
	ctx = setCaller(ctx, c.remote)
	if len(handler.Subroute) > 0 {
		ctx = setSubroute(ctx, handler.Subroute)
	}
	if msg.DeadlineMS > 0 {
		ctx, cancel = context.WithTimeout(ctx, time.Duration(msg.DeadlineMS)*time.Millisecond+c.addDeadline)
	} else {
		ctx, cancel = context.WithCancel(ctx)
	}