public void TryGetFilter()
{
#pragma warning disable CS8604 // Possible null reference argument.
#pragma warning disable CS8602 // Dereference of a possibly null reference.
var items = StateItem.All;
ListCollectionView view = new(items);
FilterPresenter? filterPresenter = FilterPresenter.Get(view);
Assert.IsNotNull(filterPresenter);
EnumFilterInitializer initializer = new();
EnumFilter <StateEnum>?filter = initializer.TryCreateFilter(filterPresenter, nameof(StateItem.State)) as EnumFilter <StateEnum>;
Assert.IsNotNull(filter);
Assert.IsFalse(filter.IsActive);
Assert.AreSame(filterPresenter, filter.FilterPresenter);
Assert.AreEqual(items.Count, view.Count);
List <StateEnum> selected = new(new StateEnum[] { StateEnum.State1, StateEnum.State4 });
List <StateEnum> unselected = new();
filter.SelectedValuesChanged(addedItems: selected, removedItems: unselected);
Assert.IsTrue(filter.IsActive);
var filtered = FilterPresenterTest.GetCollection(view);
Assert.AreEqual(selected.Count, filtered.Count);
Assert.AreEqual(selected[0], ((StateItem)filtered[0]).State);
Assert.AreEqual(selected[1], ((StateItem)filtered[1]).State);
//filterPresenter.IsFilterActive = false;
filtered = FilterPresenterTest.GetCollection(view);
Assert.AreEqual(items.Count, filtered.Count);
#pragma warning restore CS8602 // Dereference of a possibly null reference.
#pragma warning restore CS8604 // Possible null reference argument.
}
