tcpListener, ok := l.(*net.TCPListener)
	if !ok {
		t.Fatalf("failed to assert to net.TCPListener")
	}

	var wg sync.WaitGroup
	wg.Add(1)
	go func() {
		defer wg.Done()

		tcpConn, terr := tcpListener.AcceptTCP()
		if terr != nil {
			t.Errorf("failed to accept new connection. %v", terr)
			return
		}
		deadlineconn := New(tcpConn)
		deadlineconn.WithReadDeadline(time.Second)
		deadlineconn.WithWriteDeadline(time.Second)