public ChatTreeViewModel(TreeViewModelBase parent, ChatTreeItem value)
            : base(parent)
        {
            if (value == null) throw new ArgumentNullException(nameof(value));

            this.Value = value;
        }
        public ChatTreeViewItem(ChatTreeItem value)
            : base()
        {
            if (value == null) throw new ArgumentNullException("value");

            base.Header = _header;

            base.RequestBringIntoView += (object sender, RequestBringIntoViewEventArgs e) =>
            {
                e.Handled = true;
            };

            this.Value = value;
        }