nodesToReset = new HashSet();
    BrowserUI()    {        sorter = new ViewerSorter();        listener = new TreeExpansionListener() {            public void treeCollapsed(TreeExpansionEvent e) {                onNodeNavigation(e, false);            }            public void treeExpanded(TreeExpansionEvent e) {                onNodeNavigation(e, true);              }           };    }