*/
    public String normalize(final String enc) {
        if (StringUtil.isBlank(enc)) {
            return defaultEncoding;
        }

        final String newEnc = encodingMap.get(toLowerCase(enc));
        if (StringUtil.isBlank(newEnc)) {
            return enc;
        }
        return newEnc;
    }

    /**

    }

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

     * @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) {

        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<>();

    }

    private AuthScope getAuthScope() {
        if (StringUtil.isBlank(getHostname())) {
            return AuthScope.ANY;
        }

        int p;
        if (getPort() == null) {
            p = AuthScope.ANY_PORT;
        } else {
            p = getPort();
        }

        String r = getAuthRealm();
        if (StringUtil.isBlank(r)) {
            r = AuthScope.ANY_REALM;
        }

     */
    @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

     * @throws CrawlerSystemException if the MIME type is blank or maxLength is negative
     */
    public void addMaxLength(final String mimeType, final long maxLength) {
        if (StringUtil.isBlank(mimeType)) {
            throw new CrawlerSystemException("MIME type is a blank.");
        }
        if (maxLength < 0) {
            throw new CrawlerSystemException("The value of maxLength is invalid.");
        }

     *
     * @param key   the key of the feature
     * @param value the value of the feature
     */
    public void addFeature(final String key, final String value) {
        if (StringUtil.isBlank(key) || StringUtil.isBlank(value)) {
            throw new CrawlerSystemException("key or value is null.");
        }

        featureMap.put(key, value);
    }

    /**
     * Adds a property to the extractor.

     * @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) {