public static function fromPKC(Certificate $cert): IssuerSerial
    {
        $tbsCert = $cert->tbsCertificate();
        $issuer = new GeneralNames(new DirectoryName($tbsCert->issuer()));
        $serial = $tbsCert->serialNumber();
        $uid = $tbsCert->hasIssuerUniqueID() ? $tbsCert->issuerUniqueID() : null;
        return new self($issuer, $serial, $uid);
    }