void OnGUI()
        {
            bool server = _appType.HasFlag(ApplicationType.Server);
            bool client = _appType.HasFlag(ApplicationType.Client);

            bool firstStart = !server && !client && !_debugReplication;

            GUI.enabled = client || firstStart;
            server      = EditorGUILayout.Toggle("Server", server);

            GUI.enabled = server || firstStart;
            client      = EditorGUILayout.Toggle("Client", client);
            GUI.enabled = true;

            _debugReplication = EditorGUILayout.Toggle("Debug Replication", _debugReplication);
            _debugTransport   = EditorGUILayout.Toggle("Debug Transport", _debugTransport);

            _appType  = ApplicationType.None;
            _appType |= server ? ApplicationType.Server : ApplicationType.None;
            _appType |= client ? ApplicationType.Client : ApplicationType.None;

            if (GUILayout.Button("Save"))
            {
                Save();
            }
        }