assertTrue(fieldConfigs.getConfig("test").isEmpty());
    }

    public void test_values() {
        final Map<String, String> params = Maps.of("foo", "bar");
        FieldConfigs fieldConfigs = new FieldConfigs(params);
        assertTrue(fieldConfigs.getConfig("test").isEmpty());
        assertFalse(fieldConfigs.getConfig("foo").isEmpty());

     * @return an OptionalThing containing the Config if the field exists and has a non-blank value,
     *         otherwise an empty OptionalThing
     */
    public OptionalThing<Config> getConfig(final String fieldName) {
        final String value = params.get(fieldName);
        if (StringUtil.isNotBlank(value)) {
            return OptionalThing.of(new Config(value));
        }

        final Map<String, Object> newDataMap = new LinkedHashMap<>();
        for (final Map.Entry<String, Object> e : dataMap.entrySet()) {
            if (fieldConfigs.getConfig(e.getKey()).map(FieldConfigs.Config::isOverwrite).orElse(false)
                    && e.getValue() instanceof final Object[] values && values.length > 0) {
                newDataMap.put(e.getKey(), values[values.length - 1]);

        final String body = documentHelper.getContent(crawlingConfig, responseData, bodyBase, dataMap);
        putResultDataBody(dataMap, fessConfig.getIndexFieldContent(), body);
        if ((fieldConfigs.getConfig(fessConfig.getIndexFieldCache())
                .map(org.codelibs.fess.crawler.util.FieldConfigs.Config::isCache)

        final String fileName = getFileName(url, urlEncoding);
        putResultDataContent(dataMap, responseData, fessConfig, crawlingConfig, documentHelper, body, fileName);
        if ((fieldConfigs.getConfig(fessConfig.getIndexFieldCache())
                .map(org.codelibs.fess.crawler.util.FieldConfigs.Config::isCache)