}

    @Test
    public void test_user_businessCategory() {
        final User user = new User();
        assertNull(user.getBusinessCategory());

        user.setBusinessCategory("Engineering");
        assertEquals("Engineering", user.getBusinessCategory());
    }

    @Test
    public void test_user_departmentNumber() {
        final User user = new User();

                        .forEach(v -> modifyDeleteEntry(modifyList, attrX121Address, v)));
        final String attrBusinessCategory = fessConfig.getLdapAttrBusinessCategory();
        OptionalUtil.ofNullable(user.getBusinessCategory())
                .filter(StringUtil::isNotBlank)
                .ifPresent(s -> modifyReplaceEntry(modifyList, attrBusinessCategory, s))