authors[pr.author.login] = pr.author
        is_lang = False
        for label in pr.labels.nodes:
            if label.name == "lang-all":
                is_lang = True
                break
        for review in pr.reviews.nodes:
            if review.author:
                authors[review.author.login] = review.author
                if is_lang:
                    translation_reviewers[review.author.login] += 1

     * @param regex The regular expression to match URLs.
     * @param client The CrawlerClient instance.
     */
    public void addClient(final String regex, final CrawlerClient client) {
        if (StringUtil.isBlank(regex)) {
            throw new CrawlerSystemException(
                    "URL pattern regular expression is null or blank. Cannot register client without a valid pattern.");
        }
        if (client == null) {

                        original,
                        isAny(relocation.target.getGroupId()) ? null : relocation.target.getGroupId(),
                        isAny(relocation.target.getArtifactId()) ? null : relocation.target.getArtifactId(),
                        isAny(relocation.target.getClassifier()) ? null : relocation.target.getClassifier(),
                        isAny(relocation.target.getExtension()) ? null : relocation.target.getExtension(),

    }

    @Override
    public String customizeActionMappingRequestPath(final String requestPath) {
        if (StringUtil.isBlank(requestPath)) {
            return null;
        }
        final String virtualHostKey = ComponentUtil.getVirtualHostHelper().getVirtualHostKey();
        if (StringUtil.isBlank(virtualHostKey)) {
            return null;
        }
        final String prefix = "/" + virtualHostKey;

        if (list == null) {
            final String value = getSystemProperty(Constants.DEFAULT_SORT_VALUE_PROPERTY);
            if (StringUtil.isBlank(value)) {
                list = Collections.emptyList();
            } else {
                final Set<String> keySet = new HashSet<>();

                        if (!mappingList.isEmpty()) {
                            elevateWordToLabelBhv.batchInsert(mappingList);
                        }
                    } else if (StringUtil.isBlank(reading) && StringUtil.isBlank(boost)) {
                        elevateWordBhv.delete(elevateWord);
                        final String id = elevateWord.getId();

     */
    @Test
    public void testIsBlank() throws Exception {
        assertEquals("1", true, StringUtil.isBlank(" "));
        assertEquals("2", true, StringUtil.isBlank(""));
        assertEquals("3", false, StringUtil.isBlank("a"));
        assertEquals("4", false, StringUtil.isBlank(" a "));
    }

    /**
     * @throws Exception
     */
    @Test

     * @param u the URL string to extract host from
     * @return the host name, or empty string if URL is blank, or unknown hostname if parsing fails
     */
    default String getHost(final String u) {
        if (StringUtil.isBlank(u)) {
            return StringUtil.EMPTY; // empty
        }

        String url = u;
        final String originalUrl = url;

        int idx = url.indexOf("://");
        if (idx >= 0) {

     * @return the OSDD file
     */
    protected File getOsddFile() {
        if (!isOsddLinkEnabled()) {
            logger.debug("OSDD is disabled.");
            return null;
        }
        if (StringUtil.isBlank(osddPath)) {
            logger.info("OSDD file is not found.");
            return null;
        }
        final String path = LaServletContextUtil.getServletContext().getRealPath(osddPath);
        if (path == null) {

     * @return the default groups
     */
    protected static String[] getDefaultGroupsAsArray() {
        final String value = ComponentUtil.getFessConfig().getSystemProperty("oic.default.groups");
        if (StringUtil.isBlank(value)) {
            return StringUtil.EMPTY_STRINGS;
        }
        return split(value, ",").get(stream -> stream.filter(StringUtil::isNotBlank).map(String::trim).toArray(n -> new String[n]));
    }

    /**