final Map<String, List<String>> frontMatter = visitor.getData();
        for (final Map.Entry<String, List<String>> entry : frontMatter.entrySet()) {
            final String key = "frontmatter." + entry.getKey();
            final List<String> values = entry.getValue();
            if (values != null && !values.isEmpty()) {
                extractData.putValues(key, values.toArray(new String[0]));
            }
        }

                parser.setFeature(entry.getKey(), "true".equalsIgnoreCase(entry.getValue()));
            }

            // property
            for (final Map.Entry<String, String> entry : propertyMap.entrySet()) {
                parser.setProperty(entry.getKey(), entry.getValue());
            }

            return parser;
        } catch (final Exception e) {

                for (final Map.Entry<String, List<String>> entry : metadataMap.entrySet()) {
                    final List<String> values = entry.getValue();
                    extractData.putValues(entry.getKey(), values.toArray(new String[0]));
                }
            }

            return extractData;
        } catch (final IOException e) {
            throw new ExtractException("Failed to parse JSON content", e);

                for (final Map.Entry<String, List<String>> logEntry : fieldLogMap.entrySet()) {
                    for (final String value : logEntry.getValue()) {
                        searchLog.addSearchFieldLogValue(logEntry.getKey(), StringUtils.abbreviate(value, queryMaxLength));
                    }
                }
            }

            for (final String s : fessConfig.getSearchlogRequestHeadersAsArray()) {

                            final Map<String, Object> valueCount = new HashMap<>(2, 1f);
                            valueCount.put("value", e.getKey());
                            valueCount.put("count", e.getValue());
                            return valueCount;
                        }).collect(Collectors.toList()));
                        return fieldMap;

     */
    public synchronized void register(final CrawlerClientFactory crawlerClientFactory) {
        clientMap.entrySet().stream().forEach(e -> load(crawlerClientFactory, e.getKey(), e.getValue()));
        clientFactoryList.add(crawlerClientFactory);
        if (clientFactoryList.size() > maxClientFactorySize) {
            clientFactoryList.remove(0);
        }
    }

    /**

        assertArgumentNotNull("bundle", bundle);

        final Map<String, String> ret = newHashMap();
        for (final Enumeration<String> e = bundle.getKeys(); e.hasMoreElements();) {
            final String key = e.nextElement();
            final String value = bundle.getString(key);
            ret.put(key, value);
        }
        return ret;
    }

        // Clean up old consecutive failure counters
        consecutiveFailures.entrySet().removeIf(entry -> {
            String key = entry.getKey();
            Long lastFailure = lastFailureTimes.get(key);
            return lastFailure == null || now - lastFailure > FAILURE_RECOVERY_TIME * 2;
        });

        // Update connection metrics

        try {
            final List<Tag> tagList = tags.entrySet()
                    .stream()
                    .map(e -> Tag.builder().key(e.getKey()).value(e.getValue()).build())
                    .collect(Collectors.toList());

            final PutObjectTaggingRequest request = PutObjectTaggingRequest.builder()
                    .bucket(bucket)

                queryBuf.append(URLUtil.encode(entry.getKey(), Constants.UTF_8));
                formBuf.append("<input type=\"hidden\" name=\"");
                formBuf.append(StringEscapeUtils.escapeHtml4(entry.getValue()));
                formBuf.append("\" value=\"");
                formBuf.append(StringEscapeUtils.escapeHtml4(entry.getKey()));
                formBuf.append("\"/>");
            }