private void OnGUI()
        {
            m_ScrollPosition = EditorGUILayout.BeginScrollView(m_ScrollPosition, GUILayout.Height(120f));
            {
                m_SelectionList.Items = m_Items;
                EditorGUILayout.PropertyField(m_ItemsProp, true);
                m_ItemsProp.serializedObject.ApplyModifiedProperties();
            }
            EditorGUILayout.EndScrollView();

            EditorGUILayout.Space();
            GUI.enabled = false;
            EditorGUILayout.TextField("Last Selected Item", m_LastSelectedItem);
            GUI.enabled = true;
            m_SelectionList.DrawLayout();
        }