fmt.Println("Got request with initial payload", p, "from", GetCaller(ctx context.Context))
        fmt.Println("Subroute:", GetSubroute(ctx))
        for {
            select {
            case <-ctx.Done():
                return nil
            case req, ok := <-in:
                if !ok {
                    break
                }

	// 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")
				}