/**
  * create an instance of Sitemap_Base using sitemap
  *
  * @return void
  * @author Andy Bennett
  */
 public static function instance()
 {
     if (self::$instance == NULL) {
         self::$instance = Sitemap_Base::factory('sitemap');
     }
     return self::$instance;
 }
 public static function instance()
 {
     if (self::$instance == NULL) {
         self::$instance = Sitemap_Base::factory('admin');
         $xml = self::$instance->get_sitemap();
         if (Kohana::find_file('config', 'adminurls')) {
             $urls = Kohana::config('adminurls');
             foreach ($urls as $url) {
                 $tmp = $xml->items->addChild('item');
                 foreach ($url as $k => $v) {
                     $tmp->addAttribute($k, $v);
                 }
             }
             self::$instance->set_xml($xml->asXML());
         }
     }
     return self::$instance;
 }