// Arrange & Act
        SMBSignatureValidationException ex = new SMBSignatureValidationException();

        // Assert
        assertNull(ex.getMessage(), "Default ctor should not set a message");
        assertNull(ex.getCause(), "Default ctor should not set a cause");
        assertTrue(ex instanceof SmbException, "Should be an SmbException subtype");

        // Arrange & Act
        SmbUnsupportedOperationException ex = new SmbUnsupportedOperationException();

        // Assert
        assertEquals("Operation is not supported with the negotiated capabilities", ex.getMessage(),
                "Default message should match the class contract");
        assertNull(ex.getCause(), "No cause expected from default constructor");
        assertTrue(ex instanceof SmbException, "Should be an SmbException");

        return connection.getDate();
    }

    @Override
    public long getLastModified() {
        try {
            handshake();
        } catch (final IOException ex) {}
        return connection.getLastModified();
    }

    @Override
    public String getHeaderField(final String header) {
        try {
            handshake();
        } catch (final IOException ex) {}

        // Act & Assert: both UnknownHostException and IOException should become CIFSException (SmbException)
        CIFSException ex = assertThrows(CIFSException.class, () -> trace.connectWrapException(loc));
        assertTrue(ex.getMessage() != null && ex.getMessage().contains("Failed to connect to server"));
        assertSame(thrown, ex.getCause());
    }

    @Test
    @DisplayName("connectWrapException: rethrows SmbException unchanged")

    private final RuntimeException ex;

    private ThrowingIterator(RuntimeException ex) {
      this.ex = ex;
    }

    @Override
    public boolean hasNext() {
      // IteratorTester doesn't expect exceptions for hasNext().
      return true;
    }

    @Override
    public E next() {
      ex.fillInStackTrace();
      throw ex;
    }

    @Override

                        try {
                            handlerClass = Class.forName(className);
                        } catch (final Exception ex) {
                            log.debug("Failed to load handler class " + className, ex);
                        }
                        if (handlerClass == null) {
                            handlerClass = ClassLoader.getSystemClassLoader().loadClass(className);

    void getSessionKey_throws() throws CIFSException {
        doThrow(new CIFSException("session key failure")).when(session).getSessionKey();

        CIFSException ex = assertThrows(CIFSException.class, () -> session.getSessionKey());
        assertTrue(ex.getMessage().contains("failure"));
        verify(session).getSessionKey();
    }

    // Happy path: transport is returned and verified
    @Test

        // Act + Assert: exception is propagated with message
        CIFSException ex = assertThrows(CIFSException.class, () -> handle.ensureDFSResolved());
        assertEquals("DFS resolution failed", ex.getMessage());
        verify(handle, times(1)).ensureDFSResolved();
    }

    @ParameterizedTest

                    exceptions.add(e);
                }
            }
        }
        if (!exceptions.isEmpty()) {
            IllegalStateException ex = new IllegalStateException("Could not close commandRegistries");
            exceptions.forEach(ex::addSuppressed);
            throw ex;
        }
    }

    private final RuntimeException ex;

    private ThrowingIterator(RuntimeException ex) {
      this.ex = ex;
    }

    @Override
    public boolean hasNext() {
      // IteratorTester doesn't expect exceptions for hasNext().
      return true;
    }

    @Override
    public E next() {
      ex.fillInStackTrace();
      throw ex;
    }

    @Override