final List<String> pagingQueryList = new ArrayList<>();
        if (form.ex_q != null) {
            stream(form.ex_q).of(stream -> stream.filter(StringUtil::isNotBlank)
                    .distinct()
                    .forEach(q -> pagingQueryList.add("ex_q=" + LaFunctions.u(q))));
        }
        if (StringUtil.isNotBlank(form.sort)) {
            pagingQueryList.add("sort=" + LaFunctions.u(form.sort));

        return LaRequestUtil.getOptionalRequest().map(req -> {
            @SuppressWarnings("unchecked")
            final List<String> pagingQueryList = (List<String>) req.getAttribute(Constants.PAGING_QUERY_LIST);
            if (pagingQueryList != null) {
                final String prefix;
                if (query != null) {
                    prefix = "ex_q=" + query.split(":")[0] + "%3A";

    // Request and Search Constants
    // ============================================================

    /** Paging query list parameter name. */
    public static final String PAGING_QUERY_LIST = "pagingQueryList";

    /** Request languages parameter name. */
    public static final String REQUEST_LANGUAGES = "requestLanguages";

    /** Request page size parameter name. */