public static void MoveTransformsSource(int from, int to) { var gameObject = new UnityEngine.GameObject(); try { var rect = new Mux.Markup.RectTransform(); var transformsSource = new ObservableCollection <int> { 2, 3 }; rect.TransformsSource = transformsSource; rect.TransformTemplate = new DataTemplate(() => new Mux.Markup.RectTransform()); rect.AddTo(gameObject); var transforms = rect.Cast <Mux.Markup.RectTransform>().ToArray(); transformsSource.Move(from, to); Assert.AreEqual(1, transforms[0].Body.GetSiblingIndex()); Assert.AreEqual(0, transforms[1].Body.GetSiblingIndex()); } finally { UnityEngine.Object.Destroy(gameObject); } }