static getSitemapUrls(sitemapXml) {
    const urls = [];
    sitemapXml.replace(/<loc>([^<]+)<\/loc>/g, (_, url) => {
      const unescapedUrl = Helper.unescape(url);
      urls.push(unescapedUrl);
      return null;
    });
    return urls;
  }
@param {!string} sitemapXml
@return {!Array<!string>}