public IEnumerator sendToMultiplayerTest()
        {
            UnityLogger logger = new UnityLogger();
            HostManager host   = new GameObject(nameof(HostManager)).AddComponent <HostManager>();

            host.logger = logger;
            host.start();
            ClientManager[]          clients     = new ClientManager[5];
            Dictionary <int, object> receivedDic = new Dictionary <int, object>();

            for (int i = 0; i < clients.Length; i++)
            {
                clients[i] = new GameObject(nameof(ClientManager)).AddComponent <ClientManager>();
                int localI = i;
                clients[i].onReceive += (id, obj) =>
                {
                    receivedDic.Add(clients[localI].id, obj);
                    return(Task.CompletedTask);
                };
                clients[i].logger = logger;
                clients[i].start();
                Task task = clients[i].join(Dns.GetHostEntry(Dns.GetHostName()).AddressList.FirstOrDefault(ip => ip.AddressFamily == AddressFamily.InterNetwork)?.ToString(), host.port);
                yield return(new WaitUntil(() => task.IsCompleted));
            }
            Task <int> sendTask = clients[0].send(1);

            yield return(new WaitUntil(() => sendTask.IsCompleted && clients.All(c => receivedDic.Keys.Contains(c.id))));

            Assert.True(sendTask.IsCompleted);
            Assert.AreEqual(1, sendTask.Result);
            Assert.True(clients.All(c => receivedDic.ContainsKey(c.id) && receivedDic[c.id] is int i && i == 1));
        }