function isUTF8()
    {
        $string = (string) $this;
        if (function_exists('utf8_decode'))
            $decodedStr = strlen(utf8_decode($string));
        elseif (function_exists('mb_convert_encoding'))
            $decodedStr = strlen(utf8_decode($string));
        else
            $decodedStr = $string;


        return strlen($string) != strlen($decodedStr);
    }