// Spy to override getPasswordAsCharArray() to return null
        JAASAuthenticator spyAuth = spy(new JAASAuthenticator("DOM", "user", null));
        when(spyAuth.getPasswordAsCharArray()).thenReturn(null);

        PasswordCallback pc = new PasswordCallback("pass:", false);
        spyAuth.handle(new Callback[] { pc });

        // Since getPasswordAsCharArray() returned null, handler should not set a password

    @Mock
    private Configuration mockConfig;

    private SmbComSeekResponse response;

    @BeforeEach
    void setUp() {
        // Setup mock configuration to avoid NPE
        when(mockConfig.getPid()).thenReturn(12345);
        response = new SmbComSeekResponse(mockConfig);
    }

    /* ------------------------------------------------------------------ */

    private Smb2Lock[] testLocks;
    private Smb2LockRequest request;

    @BeforeEach
    void setUp() {
        MockitoAnnotations.openMocks(this);
        when(mockContext.getConfig()).thenReturn(mockConfig);

        testFileId = new byte[16];
        new SecureRandom().nextBytes(testFileId);

        testLocks = new Smb2Lock[] { new Smb2Lock(0L, 100L, Smb2Lock.SMB2_LOCKFLAG_EXCLUSIVE_LOCK) };

        void testCircularReferenceInRootCause() {
            // Create a mock exception that could have circular reference
            Exception rootCause = mock(Exception.class);
            when(rootCause.getMessage()).thenReturn("Mocked exception");

            TransportException exception = new TransportException("Test", rootCause);

            assertEquals(rootCause, exception.getRootCause());

    }

    @Test
    public void testIsValid() {
        SmbNegotiationRequest request = mock(SmbNegotiationRequest.class);
        when(request.isSigningEnforced()).thenReturn(true);
        response.getServerData().signaturesEnabled = true;

        assertTrue(response.isValid(mockContext, request));
        assertTrue(response.isSigningNegotiated());

        // Mock the request buffer
        DfsReferralRequestBuffer mockRequest = mock(DfsReferralRequestBuffer.class);
        when(mockRequest.encode(any(byte[].class), anyInt())).thenReturn(10);

        // Inject mock request
        Field requestField = Trans2GetDfsReferral.class.getDeclaredField("request");
        requestField.setAccessible(true);

                mockedKeyDerivation.when(
                        () -> Smb3KeyDerivation.deriveSigningKey(eq(Smb2Constants.SMB2_DIALECT_0300), any(byte[].class), any(byte[].class)))
                        .thenReturn(derivedKey);

                Smb2SigningDigest digest = new Smb2SigningDigest(sessionKey, Smb2Constants.SMB2_DIALECT_0300, null);
                assertNotNull(digest);

                mockedKeyDerivation.verify(

    void getConfig_delegatesToContext() {
        // Arrange
        CIFSContext ctx = mock(CIFSContext.class);
        Configuration cfg = mock(Configuration.class);
        when(ctx.getConfig()).thenReturn(cfg);
        SmbTreeConnectionTrace trace = new SmbTreeConnectionTrace(ctx);

        // Act
        Configuration result = trace.getConfig();

        // Assert
        assertSame(cfg, result);

    TestHashSet<Entry<String>> entrySet = new TestHashSet<>();
    when((Comparator<Comparable<String>>) toCopy.comparator())
        .thenReturn(Ordering.<Comparable<String>>natural());
    when(toCopy.entrySet()).thenReturn(entrySet);
    ImmutableSortedMultiset<String> unused = ImmutableSortedMultiset.copyOfSorted(toCopy);
    assertTrue(entrySet.toArrayCalled);
  }

        };

        URL url = new URL("http://custom.protocol/path");

        // Configure the mock factory to return our handler for the 'http' protocol.
        when(mockFactory.createURLStreamHandler("http")).thenReturn(mockStreamHandler);

        Handler.setURLStreamHandlerFactory(mockFactory);

        URLConnection connection = handler.openConnection(url);