// In this test, we expect IOException when endpoint is blank
        try {
            conn.connect();
            fail("Should throw IOException when endpoint is not set");
        } catch (IOException e) {
            assertTrue(e.getMessage().contains("endpoint is blank"));
        }
    }

    /**
     * Test thread-safety of connect() method.

        // In this test, we expect IOException when project ID is blank
        try {
            conn.connect();
            fail("Should throw IOException when project ID is not set");
        } catch (IOException e) {
            assertTrue(e.getMessage().contains("GCS_PROJECT_ID is blank"));
        }
    }

    /**
     * Test thread-safety of connect() method.

    }

    /**
     * Extracts the virtual host key from a RelatedQuery entity.
     * If the virtual host is blank or null, returns an empty string.
     *
     * @param entity the RelatedQuery entity to extract the host key from
     * @return the virtual host key, or empty string if blank or null
     */
    protected String getHostKey(final RelatedQuery entity) {
        final String key = entity.getVirtualHost();

    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) {
            throw new CrawlerSystemException("CrawlerClient instance is null. Cannot register null client.");
        }

     *
     * @param key       The key associated with the extractor. Must not be null or blank.
     * @param extractor The extractor to add. Must not be null.
     */
    public void addExtractor(final String key, final Extractor extractor) {
        if (StringUtil.isBlank(key)) {
            throw new CrawlerSystemException("Extractor key (MIME type) is null or blank. Cannot register extractor without a valid key.");
        }

     * <ul>
     * <li>Checks if username and password are not blank</li>
     * <li>Verifies LDAP admin is enabled for the user</li>
     * <li>Confirms the user exists in LDAP directory</li>
     * </ul>
     *
     * @param username the username of the user (must not be null or blank)
     * @param password the new password (must not be null or blank)
     * @return true if the password was changed successfully, false otherwise

        chars[0] = Character.toUpperCase(chars[0]);
        return new String(chars);
    }

    /**
     * Returns true if the string is blank.
     *
     * @param str
     *            the string to check
     * @return {@literal true} if the string is blank
     */
    public static boolean isBlank(final String str) {
        if (str == null || str.length() == 0) {
            return true;
        }

        // Null-safety: return null for blank templates
        // Early return is safe here as no resources have been allocated yet
        if (StringUtil.isBlank(template)) {
            if (logger.isDebugEnabled()) {
                logger.debug("Template is blank, returning null");
            }
            return null;
        }

                    "S3 endpoint is blank. Please set the S3_ENDPOINT environment variable or endpoint parameter.");
        }
        final String accessKey = getInitParameter("accessKey", null, String.class);
        if (StringUtil.isBlank(accessKey)) {
            throw new CrawlingAccessException(
                    "S3 access key is blank. Please set the S3_ACCESS_KEY environment variable or accessKey parameter.");

                    "Storage endpoint is blank. Please set the STORAGE_ENDPOINT environment variable or endpoint parameter.");
        }
        builder.endpoint(endpoint);
        final String accessKey = getInitParameter("accessKey", null, String.class);
        if (StringUtil.isBlank(accessKey)) {
            throw new CrawlingAccessException(