List list = CollectionSorter.sortImageDisplay(nodes);
ViewerSorter sorter = new ViewerSorter(nodes); List list = sorter.sort();
    void buildTree(Set nodes)    {        if (nodes.size() == 0) {            getTreeModel();            DefaultMutableTreeNode childNode =                 new DefaultMutableTreeNode("Empty");            DefaultTreeModel tm= (DefaultTreeModel) view.getModel();            tm.insertNodeInto(childNode, root, root.getChildCount());        } else {            List list = CollectionSorter.sortImageDisplay(nodes);            Iterator i = list.iterator();            while (i.hasNext())                buildTreeNode((ImageDisplay) i.next());        }    }