void testToStringWithNullChallengeThrowsNPE() {
            UniAddress dc = mock(UniAddress.class);
            when(dc.toString()).thenReturn("ANYSERVER");

            NtlmChallenge nc = new NtlmChallenge(null, dc);

            // Hexdump.toHexString will throw NPE when accessing challenge.length
            assertThrows(NullPointerException.class, nc::toString);
        }

        @Test

        // Must use matchers for all arguments when using any matcher
        mockedStaticAuthData.when(() -> KerberosAuthData.parse(eq(1), eq(new byte[] { 0x01 }), any(Map.class)))
                .thenReturn(Collections.singletonList(mockAuthData1));
        mockedStaticAuthData.when(() -> KerberosAuthData.parse(eq(2), eq(new byte[] { 0x02 }), any(Map.class)))

    @BeforeEach
    void setUp() {
        Arrays.fill(TEST_FILE_ID, (byte) 0x42);
    }

    private void setupMockConfig() {
        when(mockConfig.getTransactionBufferSize()).thenReturn(65536);
    }

    private void setupMockContext() {
        when(mockContext.getConfig()).thenReturn(mockConfig);
    }

    @Test
    @DisplayName("Test constructor with config and control code")

    void setUp() {
        mockContext = mock(CIFSContext.class);
        mockConfig = mock(Configuration.class);
        when(mockContext.getConfig()).thenReturn(mockConfig);
        when(mockConfig.getLeaseTimeout()).thenReturn(30000);
        when(mockConfig.getMaxLeases()).thenReturn(1000);
        when(mockConfig.getLeaseBreakTimeout()).thenReturn(60);
        leaseManager = new LeaseManager(mockContext);
    }

    @AfterEach

    @Test
    @DisplayName("Should calculate MD4 hash correctly")
    void testMD4Hash() {
        // Given
        String input = "Hello World";
        byte[] data = input.getBytes();

        // When
        MessageDigest md4 = Crypto.getMD4();
        byte[] hash = md4.digest(data);

        // Then
        assertNotNull(hash);
        assertEquals(16, hash.length); // MD4 produces 128-bit hash
    }

    public void testConstructor() throws Exception {
        // Given
        String oldFileName = "oldFile.txt";
        String newFileName = "newFile.txt";

        // When
        smbComRename = new SmbComRename(config, oldFileName, newFileName);

        // Then
        assertEquals(ServerMessageBlock.SMB_COM_RENAME, smbComRename.getCommand());

        doNothing().when(mockBufferCache).releaseBuffer(buffer);

        // When & Then
        assertDoesNotThrow(() -> {
            mockBufferCache.releaseBuffer(buffer);
        }, "releaseBuffer should handle valid buffers");
    }

    @Test
    @DisplayName("getBuffer should return buffers for use")
    void testGetBufferBasicUsage() {
        // When
        byte[] buffer1 = testCache.getBuffer();

        FileInformation internalInfo = mock(FileInformation.class);

        // Set different levels
        when(basicInfo.getFileInformationLevel()).thenReturn(FileInformation.FILE_BASIC_INFO);
        when(standardInfo.getFileInformationLevel()).thenReturn(FileInformation.FILE_STANDARD_INFO);
        when(internalInfo.getFileInformationLevel()).thenReturn(FileInformation.FILE_INTERNAL_INFO);

        // Verify each has correct level

            byte[] buffer = BufferCache.getBuffer();
            assertNotNull(buffer, "Buffer should not be null even when cache is full");
            assertEquals(SmbComTransaction.TRANSACTION_BUF_SIZE, buffer.length, "Buffer should have correct size");
            buffers.add(buffer);
        }

        // When - Release all buffers back
        for (byte[] buffer : buffers) {
            BufferCache.releaseBuffer(buffer);

 */
@DisplayName("SpnegoException Tests")
class SpnegoExceptionTest extends BaseTest {

    @Test
    @DisplayName("Should create SpnegoException with default constructor")
    void testDefaultConstructor() {
        // When
        SpnegoException ex = new SpnegoException();

        // Then
        assertNotNull(ex, "Exception should be created");
        assertNull(ex.getMessage(), "Default message should be null");