public void ExtensionMethods() { System.Windows.Controls.TreeView tv = new System.Windows.Controls.TreeView(); TreeModel <string> tm = new TreeModel <string>("", new List <TreeModel <string> >() { new TreeModel <string>("section 1", new List <TreeModel <string> >() { new TreeModel <string>("sec1item1"), new TreeModel <string>("sec1item2") }), new TreeModel <string>("section 2"), }); tv.RestoreFromTreeModel(tm); TreeModel <string> result = tv.SaveToTreeModel(""); Assert.AreEqual(tm, result); }