assertTrue(ex.getMessage().contains("Failed to calculate MIC"));
    }

    @Test
    @DisplayName("calculateMIC with null data throws NPE")
    void calculateMIC_nullData() {
        assertThrows(NullPointerException.class, () -> ctx.calculateMIC(null));
    }

    @Test
    @DisplayName("verifyMIC delegates to GSS and succeeds")

        assertFalse(handle.isSMB2());
    }

    @Test
    @DisplayName("Null treeConnection throws NPE")
    void constructorNullTreeConnection() {
        // Null treeConnection throws NPE when acquire() is called
        assertThrows(NullPointerException.class, () -> new SmbTreeHandleImpl(resourceLoc, null));
    }

    @Test

   * documentation.
   */
  public void add(Runnable runnable, Executor executor) {
    // Fail fast on a null. We throw NPE here because the contract of Executor states that it throws
    // NPE on null listener, so we propagate that contract up into the add method as well.
    checkNotNull(runnable, "Runnable was null.");
    checkNotNull(executor, "Executor was null.");

    }

    @Test
    @DisplayName("Test write operations")
    void testWriteOperations() {
        byte[] dst = new byte[1024];

        // Initialize transaction buffer to avoid NPE
        transaction.setBuffer(new byte[SmbComTransaction.TRANSACTION_BUF_SIZE]);

        // Test parameter words wire format
        int paramWords = transaction.writeParameterWordsWireFormat(dst, 0);

    class CtorValidation {
        @Test
        @DisplayName("null handle throws NPE")
        void nullHandle() {
            assertThrows(NullPointerException.class, () -> new SmbPipeInputStream(null, tree));
        }

        @Test
        @DisplayName("null tree throws NPE")
        void nullTree() {
            assertThrows(NullPointerException.class, () -> new SmbPipeInputStream(handle, null));

    }

    /**
     * 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

            }
        }
        assertThrows(ClassCastException.class, () -> {
            OtherPipeHandle result = target.unwrap(OtherPipeHandle.class);
        });

        // Null input: document current behavior (NPE from isAssignableFrom)
        assertThrows(NullPointerException.class, () -> target.unwrap(null));
    }

    @Test
    @DisplayName("getPipe, getPipeType, getUncPath delegate to underlying pipe")

    }

    // --- Invalid/null usage: calling a method on null should throw NPE ---
    @Test
    void nullReference_throwsNullPointerException() {
        // Arrange
        SmbBasicFileInfo info = null;

        // Act & Assert: attempting to call any method on null should throw NPE
        Assertions.assertThrows(NullPointerException.class, () -> {

        // Constructor accepts null principal without throwing exception
        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());

        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")
    void clone_returns_copy() {
        // Arrange