public void MainViewModel_ChangeActiveItem_WhenHasContextWithNoDataListViewModel_ClearsCollectionsOnNewItem()
{
//------------Setup for test--------------------------
string errorString;
CreateFullExportsAndVm();
FirstResource.Setup(r => r.IsAuthorized(AuthorizationContext.Contribute)).Returns(true);
var firstCtx = MainViewModel.FindWorkSurfaceContextViewModel(FirstResource.Object);
var mockDataListViewModel = new Mock<IDataListViewModel>();
firstCtx.DataListViewModel = mockDataListViewModel.Object;
MainViewModel.ActiveItem = MainViewModel.Items.FirstOrDefault(c => c.WorkSurfaceViewModel.GetType() == typeof(HelpViewModel));
//------------Execute Test---------------------------
MainViewModel.ActivateItem(firstCtx);
//------------Assert Results-------------------------
mockDataListViewModel.Verify(model => model.ClearCollections(), Times.Once());
mockDataListViewModel.Verify(model => model.CreateListsOfIDataListItemModelToBindTo(out errorString), Times.Once());
}