public static function upper($value, $message = '')
{
$locale = setlocale(LC_CTYPE, 0);
setlocale(LC_CTYPE, 'C');
$valid = !ctype_upper($value);
setlocale(LC_CTYPE, $locale);
if ($valid) {
static::reportInvalidArgument(sprintf($message ?: 'Expected a value to contain uppercase characters only. Got: %s', static::valueToString($value)));
}
}