private void addSubGroup(object userData)
{
TrackContextData trackData = userData as TrackContextData;
if (trackData != null)
{
GameObject item = CutsceneItemFactory.CreateSubTrackGroup(trackData.TrackGroup, trackData.Type, trackData.Label).gameObject;
this.isExpanded = true;
Undo.RegisterCreatedObjectUndo(item, string.Format("Create {0}", item.name));
}
}