// Arrange - use a real cause so message is derived from cause.toString()
        Throwable cause = new IllegalStateException("proto mismatch");
        String expectedMessage = cause.toString();

        // Act
        SMBProtocolDowngradeException ex = new SMBProtocolDowngradeException(cause);

        // Assert - cause preserved, message derived from cause
        assertSame(cause, ex.getCause());

        // Expect the message to be set correctly and cause to be null
        assertEquals(errorMessage, e.getMessage());
        assertNull(e.getCause());
    }

    /**
     * Test the constructor with a cause.
     */
    @Test
    void testCauseConstructor() {
        Throwable cause = new RuntimeException("Root cause");
        PACDecodingException e = new PACDecodingException(cause);

    @DisplayName("Message+Cause ctor: propagates message/cause and unsuccessful status")
    void messageAndCauseConstructor_setsMessageCause_andUnsuccessfulStatus(String msg) {
        // Arrange
        Throwable cause = new IllegalStateException("root cause");

        // Act
        SMBSignatureValidationException ex = new SMBSignatureValidationException(msg, cause);

        // Assert
        if (msg == null) {

        });

        // Test throwing and catching with cause
        RuntimeException cause = new RuntimeException("Cause");
        TransportException thrown = assertThrows(TransportException.class, () -> {
            throw new TransportException(cause);
        });
        assertEquals(cause, thrown.getCause());

        // Test throwing and catching with message and cause

        // Then
        assertSame(cause, exception.getCause(), "Crypto cause should be preserved");
        assertEquals(cause.toString(), exception.getMessage(), "Message should be cause.toString() when only cause is provided");
    }

    @Test
    @DisplayName("Message and cause constructor should preserve both crypto parameters")
    void testMessageAndCauseConstructor() {

        }
    }

    @Test
    @DisplayName("Cause-only constructor: preserves provided cause; no interactions with cause")
    void causeOnlyConstructor_preservesCause_andNoInteractions() {
        // Arrange & Act
        SMBProtocolDecodingException ex = new SMBProtocolDecodingException(mockCause);

        // Assert cause propagation
        assertSame(mockCause, ex.getCause(), "Cause should be exactly the provided instance");

    void testWithCause() {
        // Given
        IllegalArgumentException cause = new IllegalArgumentException("bad arg");

        // When
        SpnegoException ex = new SpnegoException(cause);

        // Then
        assertNotNull(ex);
        assertEquals(cause, ex.getCause());
        // IOException(Throwable) sets message to cause.toString()

    }

    /**
     * Constructs a CIFS exception with the specified detail message and cause.
     *
     * @param message the detail message
     * @param cause the cause of this exception
     */
    public CIFSException(final String message, final Throwable cause) {
        super(message, cause);
    }

    /**
     * Constructs a CIFS exception with the specified detail message.
     *

    }

    /**
     * Constructs a new SMBProtocolDecodingException with the specified detail message and cause.
     *
     * @param message the detail message
     * @param cause the cause of the exception
     */
    public SMBProtocolDecodingException(final String message, final Throwable cause) {
        super(message, cause);
    }

    /**
     * Constructs a new SMBProtocolDecodingException with the specified detail message.

     * Constructs a new PAC decoding exception with the specified cause.
     * @param cause the cause of the exception
     */
    public PACDecodingException(final Throwable cause) {
        this(null, cause);
    }

    /**
     * Constructs a new PAC decoding exception with the specified detail message and cause.
     * @param message the detail message
     * @param cause the cause of the exception
     */