protected override void AddOutputBranch()
        {
            NodeLabelItem branch = new MyNodeLabelItem((Node as MyNodeGroup).GroupOutputNodes[m_outputBranches.Count], false, true);
            branch.Tag = m_outputBranches.Count;

            m_outputBranches.Add(branch);
            AddItem(branch);
        }
        protected override void AddInputBranch()
        {
            NodeLabelItem branch = new MyNodeLabelItem((Node as MyNodeGroup).GroupInputNodes[m_inputBranches.Count] , true, false);
            branch.Tag = m_inputBranches.Count;
            branch.IsPassive = true;

            m_inputBranches.Add(branch);
            AddItem(branch);
        }