assertNull(parsed.getMechanismListMIC(), "MIC should be null when absent");
    }

    @Test
    @DisplayName("toString includes flags, mechanisms and MIC in hex")
    void testToStringIncludesFields() {
        ASN1ObjectIdentifier[] mechs = new ASN1ObjectIdentifier[] { OID_KRB_LEGACY };
        int flags = NegTokenInit.REPLAY_DETECTION | NegTokenInit.SEQUENCE_CHECKING;