// Test constructor when signing is enabled
        NtlmContext context = new NtlmContext(mockAuth, true);
        assertNotNull(context);
        assertFalse(context.isEstablished());
        assertNull(context.getServerChallenge());
        assertNull(context.getSigningKey());
        assertNull(context.getNetbiosName());

    public boolean isEstablished() {
        return isEstablished;
    }

    /**
     * Gets the server's NTLM challenge bytes.
     * @return the server challenge bytes
     */
    public byte[] getServerChallenge() {
        return serverChallenge;
    }

    /**
     * Gets the signing key for message authentication.
     * @return the signing key bytes
     */
    public byte[] getSigningKey() {