private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            _chatManager = new ChatManager();

            // YOUR CODE GOES HERE

            PlaceChildWindows();
        }
 public ChatWindow(ChatManager chatManager, User user)
 {
     InitializeComponent();
     _chatManager = chatManager;
     _user = user;
     
     // YOUR CODE GOES HERE 
     
     this.Title = _user.Username;
 }