public void Remove(TransitionItem item)
 {
     set_.Transitions.Remove(item.Transition);
     sr_.SetTransitions(set_);
     Transitions.Remove(item);
 }
        public void NewTransition()
        {
            var item = new TransitionItem(this, new Transition());
            set_.Transitions.Add(item.Transition);
            sr_.SetTransitions(set_);

            Transitions.Add(item);
            SelectedTransition = item;
            item.IsEditing = true;
            return;
        }