/**
     * Constructs a new AbstractRule.
     */
    public AbstractRule() {
        // NOP
    }

    /**
     * Registers this rule with the {@link RuleManager}.
     *
     * @param index the index at which the rule should be registered
     */
    public void register(final int index) {
        final RuleManager ruleManager = crawlerContainer.getComponent("ruleManager");
        ruleManager.addRule(index, this);

    /**
     * Registers a client component with a regular expression.
     * The component will be loaded into all registered CrawlerClientFactories.
     * @param regex The regular expression to match URLs.
     * @param componentName The name of the component to register.
     */
    public synchronized void register(final String regex, final String componentName) {
        clientMap.put(regex, componentName);

    /**
     * Initializes the CrawlerClientFactory.
     * Attempts to register itself with a "crawlerClientCreator" component if available.
     */
    @PostConstruct
    public void init() {
        try {
            final CrawlerClientCreator creator = crawlerContainer.getComponent("crawlerClientCreator");
            if (creator != null) {
                creator.register(this);
            }
        } catch (final Exception e) {

        }
        latch.countDown();
    }

    /**
     * Registers a callback to be executed when the computation is complete.
     * @param consumer The callback.
     * @return The promise.
     */
    public Promise then(final Consumer<RESPONSE> consumer) {
        return promise.then(consumer);
    }

    /**
     * Registers a callback to be executed when the computation fails.

    /**
     * Constructs a new AbstractExtractor.
     */
    public AbstractExtractor() {
        // NOP
    }

    /**
     * Registers this extractor with the ExtractorFactory.
     * @param keyList The list of keys to register this extractor under.
     */
    public void register(final List<String> keyList) {
        if (keyList == null || keyList.isEmpty()) {