public void FindVisualDescendantTest()
        {
            UITester.Dispatcher.Invoke(() =>
            {
                var dummy = WPFHelper.FindVisualDescendant <Button>(null);
                Assert.IsNull(dummy);

                var treeViewItem = testTreeView.FindVisualDescendant <TreeViewItem>();
                Assert.IsNotNull(treeViewItem);
                Assert.IsInstanceOfType(treeViewItem, typeof(TreeViewItem));
            });
        }