void testIsPreferredMechDelegates() {
        SpnegoContext ctx = newContext();
        ASN1ObjectIdentifier mech = new ASN1ObjectIdentifier("1.2.840.113554.1.2.2");
        when(this.mechContext.isPreferredMech(mech)).thenReturn(true);
        assertTrue(ctx.isPreferredMech(mech));
        verify(this.mechContext, times(1)).isPreferredMech(mech);
    }

    @Test
    @DisplayName("getFlags delegates to underlying mechanism context")

        // Arrange – create a fully populated token
        ASN1ObjectIdentifier mech = new ASN1ObjectIdentifier("1.2.840.113554.1.2.2");
        byte[] tokenArray = new byte[] { 1, 2, 3 };
        byte[] mic = new byte[] { 9, 9, 9 };
        NegTokenTarg original = new NegTokenTarg(NegTokenTarg.ACCEPT_COMPLETED, mech, tokenArray, mic);

        // Act – serialise and parse back
        byte[] bytes = original.toByteArray();

                fields.add(new DERTaggedObject(true, 0, new ASN1Enumerated(res)));
            }
            final ASN1ObjectIdentifier mech = getMechanism();
            if (mech != null) {
                fields.add(new DERTaggedObject(true, 1, mech));
            }
            final byte[] mechanismToken = getMechanismToken();
            if (mechanismToken != null) {