class KerberosApRequestTest {

    // Helper: build a minimal, valid-looking ASN.1 AP-REQ sequence with tags 0/1/2
    private ASN1Sequence buildMinimalApReqSeq(byte apOptions) {
        ASN1EncodableVector v = new ASN1EncodableVector();
        // pvno [0] INTEGER 5
        v.add(new DERTaggedObject(true, 0, new ASN1Integer(Integer.parseInt(KerberosConstants.KERBEROS_VERSION))));
        // msg-type [1] INTEGER 14 (AP-REQ)

        ASN1EncodableVector v = new ASN1EncodableVector();

        // crealm (field 2)
        v.add(new DERTaggedObject(true, 2, new DERGeneralString(userRealm)));

        // cname (field 3)
        ASN1EncodableVector principalNameVector = new ASN1EncodableVector();
        principalNameVector.add(new DERGeneralString(userName));
        ASN1EncodableVector principalVector = new ASN1EncodableVector();

    }

    @Override
    public byte[] toByteArray() {
        try {
            final ASN1EncodableVector fields = new ASN1EncodableVector();
            final ASN1ObjectIdentifier[] mechs = getMechanisms();
            if (mechs != null) {
                final ASN1EncodableVector vector = new ASN1EncodableVector();
                for (final ASN1ObjectIdentifier mech : mechs) {
                    vector.add(mech);

            String spnegoOidOverride, Integer outerTagNoOverride, ASN1TaggedObject extraField) throws IOException {

        ASN1EncodableVector fields = new ASN1EncodableVector();
        if (mechs != null) {
            ASN1EncodableVector v = new ASN1EncodableVector();
            for (ASN1ObjectIdentifier m : mechs) {
                v.add(m);
            }