path plugin base

    // Add missing arguments not defined in the path, but added as handler.
    while (($total_arguments - $arg_counter) > 0) {
      $arg_id = 'arg_' . $arg_counter++;
      $bit = '{' . $arg_id . '}';
      // In contrast to the previous loop add the defaults here, as % was not
      // specified, which means the argument is optional.
      $defaults[$arg_id] = NULL;
      $bits[] = $bit;
    }