testEnv.put("test.key", "test.value");
        ldapUser = new LdapUser(testEnv, "testuser");

        ComponentUtil.register(new SystemHelper(), "systemHelper");

        // Register a mock LdapManager to avoid NPE
        ComponentUtil.register(new LdapManager() {
            // Override methods that are called in tests
        }, "ldapManager");
    }

    @Override
    public void tearDown() throws Exception {

        assertEquals("Not supported", ex.getMessage());
    }

    @Test
    @DisplayName("Null delegate causes NPE")
    void nullDelegate() {
        assertThrows(NullPointerException.class, () -> {
            new FileEntryAdapterIterator(parent, null, null) {
                @Override

        assertEquals(lastName.toUpperCase(), writtenLastName);
    }

    @Test
    @DisplayName("Test writeParametersWireFormat with null lastName for NET_SERVER_ENUM3 throws NPE")
    void testWriteParametersWireFormatNetServerEnum3NullLastName() throws Exception {
        String domain = "WORKGROUP";
        int serverTypes = NetServerEnum2.SV_TYPE_ALL;

    @DisplayName("run method handles null URL gracefully")
    void testRunWithNullUrl() {
        TestLocking t = new TestLocking();
        t.url = null; // Null URL
        t.numIter = 0; // No iterations to avoid NPE

        // Should not throw exception
        assertDoesNotThrow(() -> t.run(), "run() should handle null URL gracefully");
        assertEquals(1, t.numComplete, "numComplete should still be incremented");
    }

    @Test
    @DisplayName("Should handle null maximum version")
    void testNullMaximumVersion() {
        // Given
        when(mockConfig.getMaximumVersion()).thenReturn(null);

        // When/Then - Should throw NPE based on actual implementation
        assertThrows(NullPointerException.class, () -> {
            new Smb2NegotiateRequest(mockConfig, 0);
        });
    }

    @Test

            DfsReferralDataInternal result = mockReferralData.combine(null);
            assertNotNull(result);

            // Test with concrete implementation - combine with null throws NPE
            assertThrows(NullPointerException.class, () -> concreteImplementation.combine(null));
        }

        @Test
        @DisplayName("Should handle null in append")
        void testAppendWithNull() {

        sut.close();

        verify(handle, never()).close(anyLong());
    }

    // Invalid input: constructing with null handle and invoking watch() NPEs
    @Test
    @DisplayName("Null handle causes NPE on watch() (invalid input)")
    void constructor_nullHandle_watch_throwsNPE() {
        SmbWatchHandleImpl sut = new SmbWatchHandleImpl(null, 0, false);

        assertThrows(NullPointerException.class, () -> {

        void testToStringWithNullBinding() {
            // Given: Handle with null binding
            TestDcerpcHandle handleWithNullBinding = new TestDcerpcHandle(mockContext);

            // When/Then: Should throw NPE for null binding (expected behavior)
            assertThrows(NullPointerException.class, () -> handleWithNullBinding.toString());
        }

        @Test
        @DisplayName("Should handle session key retrieval")

    void resolveSids_invalidInputs() throws Exception {
        SIDCacheImpl cache = new SIDCacheImpl(mock(CIFSContext.class));
        CIFSContext ctx = mock(CIFSContext.class);

        // Null sids array -> NPE
        assertThrows(NullPointerException.class, () -> cache.resolveSids(ctx, "server", null, 0, 1));

        // Bad offset/length leads to ArrayIndexOutOfBoundsException

            oplockLevelField.setAccessible(true);
            oplockLevelField.set(notification, (byte) 0x01);

            // The implementation calls Hexdump.toHexString which throws NPE on null
            // This test verifies the actual behavior
            assertThrows(NullPointerException.class, () -> notification.toString());
        }

        @ParameterizedTest