// Test with concrete implementation - behavior depends on implementation
            // May throw NullPointerException
            try {
                concreteImplementation.append(null);
            } catch (NullPointerException e) {
                // Expected for some implementations
            }
        }
    }

    @Nested

        assertEquals("remove", ex.getMessage());
    }

    @Test
    @DisplayName("Null tree handle throws NullPointerException during construction")
    void nullTreeHandle() {
        // Arrange
        SmbTreeHandleImpl nullTree = null;

        // Act + Assert
        assertThrows(NullPointerException.class,

            assertTrue(ex.getMessage().contains("Bad textual SID format"));
        }

        @Test
        @DisplayName("Textual constructor null throws NullPointerException")
        void testTextualConstructorNull() {
            assertThrows(NullPointerException.class, () -> new SID((String) null));
        }

        @Test
        @DisplayName("Binary constructor happy path and round-trip via toByteArray")

        }

        @Test
        @DisplayName("Null buffer leads to NullPointerException from readInt2")
        void nullBuffer_throwsNPE() {
            // Arrange
            Smb2LogoffResponse resp = newResponse();

            // Act & Assert
            assertThrows(NullPointerException.class, () -> resp.readBytesWireFormat(null, 0));
        }

        @Test

        connection.setDefaultUseCaches(defaultUseCaches);
    }

    @Override
    public void setRequestProperty(final String key, final String value) {
        if (key == null) {
            throw new NullPointerException();
        }
        final List values = new ArrayList();
        values.add(value);
        boolean found = false;
        final Iterator entries = requestProperties.entrySet().iterator();

        NtlmHttpServletRequest request = new NtlmHttpServletRequest(mockRequest, null);

        // getRemoteUser() will throw NPE when trying to call getName() on null principal
        assertThrows(NullPointerException.class, () -> request.getRemoteUser());
        assertNull(request.getUserPrincipal());
        assertEquals("NTLM", request.getAuthType());
    }

    @Test

            // Then
            assertNotNull(cancel);
            assertEquals(mid, cancel.getMid());
        }

        @Test
        @DisplayName("Should throw NullPointerException when config is null")
        void testNullConfigurationThrowsException() throws Exception {
            // Given

        }

        @Test
        @DisplayName("createResponse throws NullPointerException when CIFSContext is null")
        void createResponse_nullContext_throws() {
            // Arrange
            Smb2LogoffRequest req = newRequest();

            // Act/Assert
            assertThrows(NullPointerException.class, () -> req.createResponse(null, req));
        }

        @Test

     */
    @Test
    void testUnwrap_withNullParameter() {
        when(smbTree.unwrap(null)).thenThrow(new NullPointerException("Type cannot be null"));

        assertThrows(NullPointerException.class, () -> smbTree.unwrap(null), "Should throw NullPointerException when type is null");
    }

    /**
     * Test for method interaction.
     * Verifies that unwrap and close can be used in sequence.

    }

    // Invalid: null is not allowed for valueOf
    @ParameterizedTest
    @NullSource
    @DisplayName("valueOf(null) throws NullPointerException")
    void valueOfRejectsNull(String input) {
        assertThrows(NullPointerException.class, () -> RequestParam.valueOf(input));
    }

    // Sanity: Enum.valueOf(Class, String) behaves identically to RequestParam.valueOf(String)
    @Test