public static function insert_links_to_db($arr_objs, $arr_ids, $current_time)
 {
     // process md5 id
     foreach ($arr_objs as $i => $obj) {
         if (isset($obj['host_id'])) {
             $obj['host_id'] = md5($obj['host_id']);
             $arr_objs[$i] = $obj;
         }
     }
     parent::insert_links_to_db($arr_objs, $arr_ids, $current_time);
 }
 function __construct()
 {
     parent::__construct();
 }