/**
* Converts ASCII lowercase letters in a string to uppercase.
*
* Unlike strtoupper(), which honors LC_CTYPE before PHP 8.2, the
* conversion is locale-independent and leaves every non-ASCII byte
* unchanged, as HTTP protocol elements require.
*/
public static function asciiToUpper(string $string): string
{
return strtr($string, 'abcdefghijklmnopqrstuvwxyz', 'ABCDEFGHIJKLMNOPQRSTUVWXYZ');
}