* @param form the search form containing pagination parameters
     */
    protected void searchPaging(final RenderData data, final SearchForm form) {
        RenderDataUtil.register(data, "userItems", userService.getUserList(userPager)); // page navi
        // restore from pager
        copyBeanToBean(userPager, form, op -> op.include("id"));
    }

    private void registerForms(final RenderData data) {