Map<String, Object> value = new LinkedHashMap<>();
        DocMap docMap = new DocMap(value);
        assertTrue(docMap.isEmpty());
        value.clear();

        List<String> keys = Arrays.asList("test_2", "test_0", "lang", "test_1");
        value.put(keys.get(0), true);
        value.put(keys.get(1), 1000);
        value.put(keys.get(2), "ja");
        value.put(keys.get(3), "str");

        split(fessConfig.getSuggestFieldRoles(), ",").of(stream -> stream.filter(StringUtil::isNotBlank).forEach(roleFieldNameSet::add));
        contentFieldList = Arrays.asList(stream(fessConfig.getSuggestFieldContents()).get(stream -> stream.toArray(n -> new String[n])));

        final SearchEngineClient searchEngineClient = ComponentUtil.getSearchEngineClient();