* @param data the render data
     * @param form the search form
     */
    protected void searchPaging(final RenderData data, final SearchForm form) {
        RenderDataUtil.register(data, "groupItems", groupService.getGroupList(groupPager)); // page navi

        // restore from pager
        copyBeanToBean(groupPager, form, op -> op.include("id"));
    }