String testString = null;

        // Expect a NullPointerException due to null string
        assertThrows(NullPointerException.class, () -> {
            pacString.check(testString);
        }, "A NullPointerException should be thrown for a null string with non-zero pointer.");
    }

                "The exception should be either PACDecodingException or NullPointerException.");

        if (exception instanceof PACDecodingException) {
            assertEquals("Malformed kerberos ticket", exception.getMessage(), "PAC exception should indicate malformed ticket.");
        } else if (exception instanceof NullPointerException) {
            // Empty input causes null ASN1 object, which is expected behavior

    /**
     * Ensure encode throws NPE when passed a null buffer.
     */
    @Test
    @DisplayName("Encode with null buffer throws NullPointerException")
    public void testEncodeNullBuffer() throws NdrException {
        NdrHyper hyper = new NdrHyper(5L);
        assertThrows(NullPointerException.class, () -> hyper.encode(null));
    }

    /**
     * Ensure decode throws NPE when passed a null buffer.
     */
    @Test

    void unwrap_null_type_throws() {
        TestCredentials creds = new TestCredentials("DOM", false, false, new Subject(), false);
        // Act & Assert
        NullPointerException npe = assertThrows(NullPointerException.class, () -> creds.unwrap(null));
        assertEquals("type", npe.getMessage());
    }

    @Test
    @DisplayName("clone returns a distinct copy with same properties")

        @Test
        @DisplayName("Null handle triggers NullPointerException")
        void ctor_nullHandle_throwsNPE() {
            // Act + Assert
            assertThrows(NullPointerException.class, () -> new SmbPipeOutputStream(null, tree));
        }

        @Test
        @DisplayName("Null tree handle triggers NullPointerException")
        void ctor_nullTree_throwsNPE() {
            // Arrange

                throw new NullPointerException("dir and name must be non-null");
            }
            return true;
        };

        NullPointerException npe1 = assertThrows(NullPointerException.class, () -> filter.accept(null, "x"));
        assertTrue(npe1.getMessage().contains("non-null"));

        NullPointerException npe2 = assertThrows(NullPointerException.class, () -> filter.accept(mockDir, null));

    }

    @Test
    @DisplayName("Constructor should handle null parent")
    void testConstructor_NullParent_ThrowsNPE() {
        // When & Then: Null parent should cause NullPointerException
        assertThrows(NullPointerException.class, () -> new NetServerEnumIterator(null, treeHandle, "*", 0, null));
    }

    @Test
    @DisplayName("Constructor should handle null tree handle")

        result.addFailure(new RuntimeException("RuntimeException"));
        result.addFailure(new IllegalStateException("IllegalStateException"));
        result.addFailure(new NullPointerException("NullPointerException"));

        assertEquals(4, result.getFailures().size());
        assertTrue(result.getFailures().get(0) instanceof Exception);
        assertTrue(result.getFailures().get(1) instanceof RuntimeException);

        // Close the stream
        outputStream.close();

        // When & Then - after close, tmp is null so write(int) will throw NullPointerException
        // This is the actual behavior of the implementation
        assertThrows(NullPointerException.class, () -> outputStream.write(65));
    }

    @Test
    void testWriteNullArray() throws CIFSException {
        // Given

            NtlmChallenge nc = new NtlmChallenge(null, dc);

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

        @Test
        @DisplayName("toString with null dc throws NPE")
        void testToStringWithNullDcThrowsNPE() {
            byte[] challenge = new byte[] { 1, 2, 3 };