assertNotNull(encrypted1);

        // Encrypt larger message to trigger rotation
        byte[] largeMessage = new byte[150]; // Exceed 100 byte limit
        Arrays.fill(largeMessage, (byte) 'A');

        // Should trigger automatic rotation and succeed
        byte[] encrypted2 = assertDoesNotThrow(() -> context.encryptMessage(largeMessage, 2L));

        // Register a mock file with cache
        leaseManager.registerFileCache(path, null); // Using null for simplicity in test

        // Handle lease break which should trigger cache operations
        leaseManager.handleLeaseBreak(key, Smb2LeaseState.SMB2_LEASE_NONE);

        LeaseEntry entry = leaseManager.getLease(key);
        assertNotNull(entry);

        assertEquals(NtStatus.NT_STATUS_UNSUCCESSFUL, ex.getNtStatus(), "Status should default to unsuccessful for message+cause ctor");
    }

    // Interaction: passing a mocked cause should not trigger interactions (nothing to call)
    @Test
    @DisplayName("Mocked cause: no interactions occur when stored as cause")
    void mockedCause_isStored_withoutInteraction() {
        // Arrange

    void renewOnNullReferenceThrowsNPE() {
        // Arrange: null reference to the interface
        SmbRenewableCredentials creds = null;

        // Act + Assert: invoking renew() on null triggers NullPointerException
        assertThrows(NullPointerException.class, () -> {
            // Intentional NPE through dereference of a null interface reference
            creds.renew();
        });
    }

    }

    @Test
    @DisplayName("parseURL: exact 'smb://' sets default port")
    void testParseURL_ExactRoot_DefaultPort() throws MalformedURLException {
        // Arrange & Act: constructing this URL triggers Handler.parseURL("smb://")
        Handler handler = newHandler();
        URL url = new URL(null, "smb://", handler);

        // Assert
        assertEquals("smb", url.getProtocol());

                    return buf;
                }, IllegalArgumentException.class),

                // Negative NAME_LEN (0xFFFFFFFF) causes StringIndexOutOfBoundsException
                Arguments.of("negative name length triggers SIOOBE", (java.util.function.Supplier<byte[]>) () -> {
                    byte[] tok = new byte[] { 0x04, 0x01 };
                    byte[] buf = new byte[2 + 2 + der.length + 4];
                    int p = 0;

        when(this.mechContext.getFlags()).thenReturn(0x1234);
        when(this.mechContext.initSecContext(any(byte[].class), eq(0), eq(0))).thenReturn(new byte[] { 0x01, 0x02 });

        // Act: len==0 triggers initial token construction
        byte[] out = ctx.initSecContext(null, 0, 0);

        // Assert: returns a SPNEGO token (opaque here but non-null/non-empty)
        assertNotNull(out);
        assertTrue(out.length > 0);

        for (int i = 0; i < threadCount; i++) {
            final int index = i;
            threads[i] = new Thread(() -> {
                try {
                    // Call processRequest which triggers initialization
                    client.doGet("file://nonexistent.txt");
                } catch (Exception e) {
                    // Expected for nonexistent file
                }

     */
    @Test
    @DisplayName("Pre-auth integrity hash should reset on error")
    void testPreauthHashResetOnError() throws Exception {
        // Setup invalid SMB2 state to trigger error
        setPrivateField(transport, "smb2", false);

        // Try to update preauth hash - should fail and reset
        Method updateMethod = findMethod(transport.getClass(), "updatePreauthHash", byte[].class);

        // Given
        when(mockTreeHandle.isSMB2()).thenReturn(true);
        when(mockTreeHandle.getSendBufferSize()).thenReturn(65536);
        when(mockFileHandle.isValid()).thenReturn(false, true); // First false to trigger ensureOpen, then true
        when(mockFileHandle.getFileId()).thenReturn(new byte[16]);
        when(mockFileHandle.acquire()).thenReturn(mockFileHandle);

        // Mock for ensureOpen to reopen file