public static function printCharCode($code)
    {
        if ($code === null) {
            return '<EOF>';
        }

        return $code < 0x007F
            // Trust JSON for ASCII.
            ? json_encode(self::chr($code))
            // Otherwise print the escaped form.
            : '"\\u' . dechex($code) . '"';
    }
public static function printCharCode($code)
    {
        if ($code === null) {
            return '<EOF>';
        }

        return $code < 0x007F
            // Trust JSON for ASCII.
            ? json_encode(self::chr($code))
            // Otherwise print the escaped form.
            : '"\\u' . dechex($code) . '"';
    }
@param int|null $code

@return string