public void CollapseChildren()
        {
            if (ViewModel is not ProjectExplorerViewModel viewModel)
            {
                return;
            }

            var model = viewModel.SelectedItem;
            var node  = TreeGrid.View.Nodes.GetNode(model);

            TreeGrid.CollapseAllNodes(node);
        }
 public void CollapseAll() => TreeGrid.CollapseAllNodes();