assertTrue(exception.getMessage().contains(cause.getClass().getName()));
        assertTrue(exception.getMessage().contains("Cause exception"));
    }

    public void test_constructor_withNullMessage() {
        // Test constructor with null message
        FessSystemException exception = new FessSystemException((String) null);

        assertNull(exception.getMessage());

        assertTrue(exception instanceof FessSystemException);
        assertTrue(exception instanceof RuntimeException);
    }

    public void test_constructor_withNullMessage() {
        // Test constructor with null message
        CommandExecutionException exception = new CommandExecutionException(null);

        assertNotNull(exception);
        assertNull(exception.getMessage());

        assertEquals(message, exception.getMessage());
        assertEquals(cause, exception.getCause());
        assertTrue(exception instanceof FessSystemException);
    }

    public void test_constructor_withNullMessage() {
        // Test with null message
        DataStoreException exception = new DataStoreException((String) null);

        assertNotNull(exception);
        assertNull(exception.getMessage());

        assertEquals("", exception.getUrl());
        assertEquals(message, exception.getMessage());
        assertFalse(exception.aborted());
    }

    public void test_constructor_withNullMessage() {
        // Test with null message
        String url = "http://example.com/test";
        String message = null;
        Exception cause = new RuntimeException("Error cause");

        assertEquals(message, exception.getMessage());
        assertEquals(cause, exception.getCause());
    }

    public void test_constructor_withNullMessage() {
        // Test constructor with null message
        SsoProcessException exception = new SsoProcessException((String) null);

        assertNull(exception.getMessage());

        assertNull(exception.getType());
        assertEquals(message, exception.getMessage());
        assertNull(exception.getCause());
    }

    public void test_constructor_withNullMessage() {
        // Test constructor with null message
        String type = "OAuth2";
        String message = null;
        InvalidAccessTokenException exception = new InvalidAccessTokenException(type, message);

        assertEquals(message, exception.getMessage());
        assertEquals(cause, exception.getCause());
        assertNull(exception.getMessageCode());
    }

    public void test_constructor_withNullMessage() {
        // Setup
        final VaMessenger<FessMessages> messageCode = messages -> messages.addErrorsSsoLoginError(UserMessages.GLOBAL_PROPERTY_KEY);

        assertEquals(message, exception.getMessage());
        assertEquals(cause, exception.getCause());
        assertNull(exception.getMessageCode());
    }

    public void test_constructor_withNullMessage() {
        // Setup
        final VaMessenger<FessMessages> messageCode = messages -> messages.addErrorsInvalidQueryUnknown(UserMessages.GLOBAL_PROPERTY_KEY);

        assertTrue(exception instanceof RuntimeException);
        assertTrue(exception instanceof Throwable);
    }

    /**
     * Test constructor with null message
     */
    public void test_constructor_withNullMessage() {
        CrawlerSystemException exception = new CrawlerSystemException((String) null);

        assertNotNull(exception);
        assertNull(exception.getMessage());
        assertNull(exception.getCause());