protected override void OnRowActivated(TreePath path, TreeViewColumn column)
        {
            base.OnRowActivated(path, column);
            TreeIter it;

            TreePath[] sel = Selection.GetSelectedRows();
            if (store.GetIter(out it, sel[0]))
            {
                ObjectValue val = (ObjectValue)store.GetValue(it, ObjectCol);
                if (val.Name == DebuggingService.DebuggerSession.EvaluationOptions.CurrentExceptionTag)
                {
                    DebuggingService.ShowExceptionCaughtDialog();
                }
            }
        }