internal static void DeleteItems(IEnumerable <ITimelineItem> items)
{
var tracks = items.GroupBy(c => c.parentTrack);
foreach (var track in tracks)
{
TimelineUndo.PushUndo(track.Key, "Delete Items");
}
TimelineAnimationUtilities.UnlinkAnimationWindowFromClips(items.OfType <ClipItem>().Select(i => i.clip));
EditMode.PrepareItemsDelete(ItemsUtils.ToItemsPerTrack(items));
EditModeUtils.Delete(items);
SelectionManager.RemoveAllClips();
}