public void DetachStopsListeningForChanges()
{
var region = new MockPresentationRegion();
var behavior = new RegionActiveAwareBehavior { Region = region };
var collection = region.MockActiveViews.Items;
behavior.Attach();
behavior.Detach();
ActiveAwareFrameworkElement activeAwareObject = new ActiveAwareFrameworkElement();
collection.Add(activeAwareObject);
Assert.IsFalse(activeAwareObject.IsActive);
}