ois.close();

        // Verify
        assertNotNull(deserialized);
        assertNull(deserialized.getMessage());
        assertNull(deserialized.getCause());
    }

    @Test
    public void test_stackTrace() {
        // Test that stack trace is properly maintained
        DictionaryExpiredException exception = new DictionaryExpiredException();
        StackTraceElement[] stackTrace = exception.getStackTrace();

        // Both instances should be of the same class
        assertEquals(exception1.getClass(), exception2.getClass());
    }

    @Test
    public void test_stackTrace() {
        // Test that the exception has a proper stack trace
        FessUserNotFoundException exception = new FessUserNotFoundException("testuser");

        StackTraceElement[] stackTrace = exception.getStackTrace();

        assertTrue(runtimeException instanceof RuntimeException);
        assertTrue(runtimeException instanceof Exception);
        assertTrue(runtimeException instanceof Throwable);
    }

    @Test
    public void test_stackTrace() {
        // Create a ServletException with a specific message
        String errorMessage = "Stack trace test error";
        ServletException servletException = new ServletException(errorMessage);