getLogger().debug("ExtractData: {}", extractData);
            }
            // meta
            extractData.getKeySet().stream().filter(k -> extractData.getValues(k) != null).forEach(key -> {
                final String[] values = extractData.getValues(key);
                metaDataMap.put(key, values);

                // meta -> content
                if (fessConfig.isCrawlerMetadataContentIncluded(key)) {