// When & Then - should handle null gracefully (implementation dependent)
        assertDoesNotThrow(() -> request.setFileId(null), "Should handle null file ID without throwing exception");
    }

    @Test
    @DisplayName("Should handle empty file ID")
    void testSetEmptyFileId() {
        // Given
        RequestWithFileId request = new Smb2CloseRequest(mockConfig, testFileId);

        // Assert
        assertFalse(it.hasNext(), "No next when opened with null initial");
        verify(tree, times(1)).release(); // closed in constructor
    }

    @Test
    @DisplayName("open() throwing CIFSException triggers close and rethrow")
    void constructorOpenThrows() {
        // Arrange
        stubAcquireReturnsSelf();

    }

    @Test
    @DisplayName("Test all write methods with null buffer")
    void testWriteMethodsWithNullBuffer() {
        // Even with null buffer, methods should return 0 without throwing exception
        int result = response.writeSetupWireFormat(null, 0);
        assertEquals(0, result);

        result = response.writeParametersWireFormat(null, 0);
        assertEquals(0, result);

    }

    /**
     * Test watch() method throwing CIFSException
     */
    @Test
    void testWatchThrowsCIFSException() throws CIFSException {
        // Setup mock behavior
        CIFSException expectedException = new CIFSException("Watch operation failed");
        when(watchHandle.watch()).thenThrow(expectedException);

        // Execute and verify
        CIFSException thrown = assertThrows(CIFSException.class, () -> {

        // Both resources should be closed
        verify(filter, times(2)).accept(resource);
        verify(resource, times(2)).close();
    }

    @Test
    @DisplayName("Iterator with filter throwing exception")
    void iteratorWithFilterException() throws Exception {
        // Setup: first attempt throws, second succeeds
        FileEntry entry1 = mock(FileEntry.class);

        // Mock response
        when(treeHandle.send(any(), any(), (RequestParam[]) any())).thenAnswer(invocation -> {
            return invocation.getArgument(1);
        });

        // When: Create iterator with throwing filter
        NetServerEnumIterator iterator = new NetServerEnumIterator(parent, treeHandle, "*", 0, nameFilter);

        // Then: Iterator should skip the entry (log error and continue)

    void testOpenConnection_NullSystemProperty_UsesDefaultHandlers() throws Exception {
        // This test verifies that when the system property is null, the handler
        // falls back to using default handlers without throwing NullPointerException.
        System.clearProperty("java.protocol.handler.pkgs");
        setupMockProtocolHandlers();
        URL url = new URL("http://example.com/resource");

        int securityInfo = OWNER_SECURITY_INFORMATION;

        querySecurityDesc = new NtTransQuerySecurityDesc(mockConfig, fid, securityInfo);

        // Constructor should initialize the object without throwing exceptions
        assertNotNull(querySecurityDesc);

        // Test toString contains the expected values to verify field initialization
        String str = querySecurityDesc.toString();

        verify(tree, atLeastOnce()).release();
    }

    @ParameterizedTest
    @ValueSource(strings = { "", " ", "*", "?" })
    @DisplayName("Supports various wildcard values without throwing (edge cases)")
    void wildcardEdgeCases(String wildcard) throws Exception {
        // minimal successful first response with a single entry

        // This is a design choice for this specific implementation
        assertNull(emptyIterator.next(), "This implementation returns null instead of throwing");

        // Verify remove can be called (even though no-op)
        assertDoesNotThrow(() -> emptyIterator.remove(), "remove() should be safe to call");

        // Verify still empty after operations