code: function createSitemapIndex (conf) {
    return new SitemapIndex(conf.urls,
      conf.targetFolder,
      conf.hostname,
      conf.cacheTime,
      conf.sitemapName,
      conf.sitemapSize,
      conf.xslUrl,
      conf.gzip,
      conf.callback);
  }
docs: Shortcut for `new SitemapIndex (...)`.
  
  @param   {Object}        conf
  @param   {String|Array}  conf.urls
  @param   {String}        conf.targetFolder
  @param   {String}        conf.hostname
  @param   {Number}        conf.cacheTime
  @param   {String}        conf.sitemapName
  @param   {Number}        conf.sitemapSize
  @param   {String}        conf.xslUrl
  @return  {SitemapIndex}