* Adjusts fragment size for mobile devices.
     *
     * @return the highlight information
     */
    public HighlightInfo createHighlightInfo() {
        return LaRequestUtil.getOptionalRequest().map(req -> {
            final HighlightInfo highlightInfo = new HighlightInfo();
            final String widthStr = req.getParameter(SCREEN_WIDTH);
            if (StringUtil.isNotBlank(widthStr)) {

            throw new UnsupportedOperationException("getSimilarDocHash() is not supported in this implementation");
        }

        @Override
        public HighlightInfo getHighlightInfo() {
            return new HighlightInfo();
        }
    }

    @Override
    protected void writeHeaders(final HttpServletResponse response) {

        }

        @Override
        public FacetInfo getFacetInfo() {
            return null;
        }

        @Override
        public HighlightInfo getHighlightInfo() {
            return new HighlightInfo().fragmentSize(Integer.parseInt(fessConfig.getOrDefault("rag.chat.highlight.fragment.size", "500")))