}
final ArrayList<DefaultTreeNode> nodes = new ArrayList<DefaultTreeNode>();
Utils.visitSheets(book, new SheetVisitor(){
@Override
public void handle(Sheet sheet) {
nodes.add(new DefaultTreeNode(sheet.getSheetName(), Collections.EMPTY_LIST));
}});
/**
* TODO: use i-18n instead hardcode
*/
DefaultTreeNode root = new DefaultTreeNode("Cell Reference", nodes);
DefaultTreeModel model = new DefaultTreeModel(root);
tree.setModel(model);
tree.addEventListener(Events.ON_SELECT, new EventListener() {