}

    /**
     * Adds a language to filter by.
     * @param lang The language.
     * @return This builder instance.
     */
    public SuggestRequestBuilder addLang(final String lang) {
        request.addLang(lang);
        return this;
    }

 * suggestRequest.setSize(5);
 * suggestRequest.addTag("tag1");
 * suggestRequest.addRole("role1");
 * suggestRequest.addField("field1");
 * suggestRequest.addKind("kind1");
 * suggestRequest.addLang("en");
 * suggestRequest.setSuggestDetail(true);
 * suggestRequest.setReadingConverter(new MyReadingConverter());
 * suggestRequest.setNormalizer(new MyNormalizer());
 * suggestRequest.setPrefixMatchWeight(1.5f);

        document.put("lang", "en");
        suggester.indexer().indexFromDocument(new Map[] { document });
        suggester.refresh();

        SuggestResponse response1 = suggester.suggest().setQuery("The").addLang("en").setSuggestDetail(true).execute().getResponse();
        assertEquals(0, response1.getNum());
        assertEquals(0, response1.getTotal());

            roleQueryHelper.build(SearchRequestType.SUGGEST).stream().forEach(builder::addRole);
            builder.setSize(parameter.getNum());
            stream(langs).of(stream -> stream.forEach(builder::addLang));

            stream(parameter.getTags()).of(stream -> stream.forEach(builder::addTag));
            final String key = ComponentUtil.getVirtualHostHelper().getVirtualHostKey();
            if (StringUtil.isNotBlank(key)) {