return new Vector().elements();
return new Vector<String>().elements();
    public Enumeration getItemNames( String categoryName ) {        // Get the category with the given name.        Categorized category = (Categorized) categories.get( categoryName );        // Return an empty Enumeration if we couldn't find the category.        if ( null == category ) {            return new Vector().elements();        }        // Is this a subcategory?        if ( this != category ) {            // Yup.  Pass the request on.            return category.getItemNames( categoryName );        }        // Return the names of this directory's items.        return Collections.elements( items.keySet() );    }