package sample.dms.secured;import sample.dms.DocumentDao;/** * Extends the {@link DocumentDao} and introduces ACL-related methods. *  * @author Ben Alex * @version $Id: SecureDocumentDao.java 1772 2006-12-17 00:54:13Z benalex $ * */public interface SecureDocumentDao extends DocumentDao {    /**     * @return all the usernames existing in the system.     */    public String[] getUsers();}