code: public static function register($prepend = false)
      {
          @trigger_error('Using Twig_Autoloader is deprecated since version 1.21. Use Composer instead.', E_USER_DEPRECATED);
  
          if (PHP_VERSION_ID < 50300) {
              spl_autoload_register(array(__CLASS__, 'autoload'));
          } else {
              spl_autoload_register(array(__CLASS__, 'autoload'), true, $prepend);
          }
      }
docs: Registers Twig_Autoloader as an SPL autoloader.
  
  @param bool $prepend whether to prepend the autoloader or not