public static function actionFilename($action, $dirs = null, $useNamespaces = false)
    {
        $dirs = self::path($dirs ?: self::get('atomik.dirs.actions'));
        if (($filename = self::findFile("$action.php", $dirs, $useNamespaces)) === false) {
            return $useNamespaces ? false : self::findFile("$action/index.php", $dirs);
        }
        return $filename;
    }