assertEquals("{labels.login.update}", FessLabels.LABELS_LOGIN_UPDATE);
    }

    /**
     * Test that FessLabels extends UserMessages
     */
    @Test
    public void test_extendsUserMessages() {
        assertTrue(org.lastaflute.core.message.UserMessages.class.isAssignableFrom(FessLabels.class));
    }

    /**
     * Test field count to ensure no unexpected fields are added
     */