public void CollapseAllTest() { var element = CreateCustomNode("AMember", "CategoryA.SubCategoryA.ClassA"); model.Add(element); element = CreateCustomNode("BMember", "CategoryB.SubCategoryB.ClassB"); model.Add(element); viewModel.BrowserRootCategories[1].IsExpanded = true; viewModel.BrowserRootCategories[1].SubCategories[0].IsExpanded = true; viewModel.CollapseAll(viewModel.BrowserRootCategories); Assert.IsFalse(viewModel.BrowserRootCategories[1].IsExpanded); Assert.IsFalse(viewModel.BrowserRootCategories[1].SubCategories[0].IsExpanded); }