public void BeforeEach() { _rowViewModelFactoryMock = new Mock<IRowViewModelFactory<TrackableModel, ITrackableViewModel>>(); _rowViewModelFactoryMock.Setup(f => f.Create(It.IsAny<TrackableModel>())).Returns<TrackableModel>(m => new TrackableViewModel(m)); _tracker = new Tracker<TrackableModel, ITrackableViewModel>(_rowViewModelFactoryMock.Object); var models = new Collection<TrackableModel> { new TrackableModel("test1", 1), new TrackableModel("test2", 2), new TrackableModel("test3", 3), new TrackableModel("test4", 4) }; _rows = _tracker.ConvertAndTrack(models); }