* and to parse an input stream into a {@link SitemapSet} object.
 * It uses SAX parser for XML sitemaps and XML sitemap indexes,
 * and handles potential exceptions during parsing.
 * The class also includes inner classes for handling XML sitemap and sitemap index parsing.
 */
public class SitemapsHelper {
    private static final Logger logger = LogManager.getLogger(SitemapsHelper.class);

 * during the crawling process. It extracts data, identifies child URLs, and handles
 * character set encoding.
 * <p>
 * This class extends {@link AbstractTransformer} and utilizes various helper classes
 * and components from the Fess Crawler framework, such as {@link CrawlerContainer},
 * {@link UrlConvertHelper}, and {@link EncodingHelper}.
 * </p>
 * <p>
 * The transformation process involves:
 * </p>
 * <ol>