private void RemoveAnimationTrack()
{
USUndoManager.RegisterCompleteObjectUndo(AnimationTimeline, "Remove Track");
AnimationTimeline.RemoveTrack(AnimationTrack);
AnimationTimelineHierarchy.RemoveAnimationTrack(AnimationTrack);
}
public void RemoveAnimationTrack(AnimationTrack track)
{
USUndoManager.RegisterCompleteObjectUndo(AnimationTimeline, "Add New Track");
AnimationTimeline.RemoveTrack(track);
USUndoManager.RegisterCompleteObjectUndo(USHierarchy, "Add New Track");
USHierarchy.RootItems.Remove(USHierarchy.RootItems.Where(item => ((USAnimationTimelineTrackHierarchyItem)item).AnimationTrack == track).First());
USUndoManager.DestroyImmediate(track);
}