/** Map of metadata field names to their corresponding XPath expressions. */
    protected Map<String, String> metadataXpathMap = new HashMap<>();

    /** Thread-local instance of XPathAPI for thread-safe XPath evaluation. */
    private final ThreadLocal<XPathAPI> xpathAPI = new ThreadLocal<>();

    /**
     * Creates a new HtmlExtractor instance.
     */
    public HtmlExtractor() {
        super();
    }

 * String escapedXml = XmlUtil.escapeXml("<tag>value</tag>");
 * Map<String, Object> dataMap = XmlUtil.getDataMap(accessResultData);
 * }
 * </pre>
 *
 * <h2>Thread Safety:</h2>
 * <p>
 * This class is thread-safe as it does not maintain any state.
 * </p>
 *
 * <h2>Dependencies:</h2>
 * <ul>
 *   <li>org.apache.logging.log4j.Logger</li>
 *   <li>org.apache.logging.log4j.LogManager</li>
 *   <li>org.xml.sax.InputSource</li>

 * Node singleNode = xPathAPI.selectSingleNode(contextNode, "//example[1]");
 * XPathEvaluationResult<?> result = xPathAPI.eval(contextNode, "count(//example)");
 * }
 * </pre>
 *
 * <p>Note: This class is not thread-safe. Each thread should create its own instance of XPathAPI.</p>
 *
 * @see javax.xml.xpath.XPath
 * @see javax.xml.xpath.XPathFactory
 * @see javax.xml.xpath.XPathExpressionException
 */
public class XPathAPI {

 * If the time since the last request to the host is less than the configured delay,
 * the thread waits until the delay has elapsed.
 * This class is thread-safe.
 */
public class HostIntervalController extends DefaultIntervalController {

    /** Map storing the last access time for each host. */

 *
 * <p>It uses {@code Map} and {@code Queue} data structures to hold the data. The class provides
 * methods to add, remove, clear, and retrieve data from these structures.
 *
 * <p>The class is thread-safe due to the use of {@code synchronized} keyword on methods that
 * modify the internal data structures. The internal maps are also declared as {@code volatile}
 * to ensure visibility of changes across threads.
 *

 * The class uses a static {@code idCount} to generate unique IDs for each access result.
 * The {@code idCountLock} object is used to synchronize access to the {@code idCount} variable,
 * ensuring that IDs are generated in a thread-safe manner.
 * </p>
 *
 * <p>
 * The class also provides methods to get the count of access results for a given session,
 * to delete all access results for a given session, and to delete all access results.
 * </p>
 *

     * , java.lang.String)
     */
    @Override
    public void updateSessionId(final String oldSessionId, final String newSessionId) {
        // not MT-safe
        final Queue<UrlQueueImpl<Long>> urlQueueList = dataHelper.getUrlQueueList(oldSessionId);
        // overwrite
        dataHelper.addUrlQueueList(newSessionId, urlQueueList);

        public void clearRules() {
            rules.clear();
        }

        public List<Rule> getRules() {
            return new ArrayList<>(rules);
        }
    }

    /**
     * Thread-safe implementation of RuleManager
     */
    public static class ThreadSafeRuleManager implements RuleManager {
        private final List<Rule> rules = new CopyOnWriteArrayList<>();

        @Override

            + "^\\s*data:|" //
            + "^\\s*android-app:|" //
            + "^\\s*ios-app:|" //
            + "^\\s*callto:", Pattern.CASE_INSENSITIVE);

    /** Thread-local XPathAPI instance for thread-safe XPath operations. */
    private final ThreadLocal<XPathAPI> xpathAPI = new ThreadLocal<>();

    @Override
    public ResultData transform(final ResponseData responseData) {