public void testRegeneratePrincipalName() throws Exception {
        // -- set the transaction to be committed
        setDefaultRollback(false);
        assertTrue(userManager.userExists("jonas"));
        assertFalse(userManager.userExists("jonasengman"));
        User user = (User) userManager.getPrincipal("jonas");
        user.setFirstname("Jonas");
        user.setSurname("Engman");
        endTransaction();
        startNewTransaction();

        userManager.regenerateUserName(user);
        endTransaction();
        startNewTransaction();

        assertFalse(userManager.userExists("jonas"));
        assertTrue(userManager.userExists("jonasengman"));
        // ok, restore db state
        authenticationDao.renamePrincipal("jonasengman", "jonas");

        endTransaction();
        startNewTransaction();
        assertTrue(userManager.userExists("jonas"));
        assertFalse(userManager.userExists("jonasengman"));

        // -- revert
        setDefaultRollback(true);
    }