public static function instance()
 {
     if (self::$instance === null) {
         self::$instance = new self();
     }
     return self::$instance;
 }
 function login_html($tourl, $context)
 {
     if (!Q2ANKConnect::is_ready_data()) {
         return;
     }
     echo Q2ANKConnect::instance()->get_login_button();
 }