protected function _trans()
    {
        if (!extension_loaded('intl')) {
            throw new \RuntimeException(
                'Missing Intl extension. This is required to use ' . __CLASS__ . '::trans'
            );
        }

        if(!function_exists('\transliterator_transliterate')){
            throw new \RuntimeException(
                'Intl extension does not provide transliterate feature '
                .'prior PHP 5.4.0!'
            );
        }

        $str = \transliterator_transliterate(
            "Any-Latin; NFD; [:Nonspacing Mark:] Remove; NFC;",
            $this->value
        );

        return new self($str);
    }