public void OnEnable(Rect pos, EditorWindow parent)
        {
            m_Parent   = parent;
            m_Position = pos;
            m_HorizontalSplitterRect = new Rect(
                (int)(m_Position.x + m_Position.width * m_HorizontalSplitterPercent),
                m_Position.y,
                k_SplitterWidth,
                m_Position.height);

            m_GraphCollectionTreeState = new TreeViewState();
            m_collectionTree           = new GraphCollectionTree(m_GraphCollectionTreeState, this);

            m_GraphCollectionDetailTreeState = new TreeViewState();
            m_detailTree = new GraphCollectionDetailTree(m_GraphCollectionDetailTreeState, this);

            m_collectionTree.Reload();
            m_detailTree.Reload();
        }