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

    @Test
    @DisplayName("parsing malformed token throws IOException")
    void testMalformedToken() {
        byte[] bad = new byte[] { 0x01, 0x02, 0x03 }; // not a valid ASN.1 tagged object
        assertThrows(IOException.class, () -> new NegTokenTarg(bad), "Malformed byte[] should cause IOException");
    }