assertNotSame(exception1, exception2);
        assertFalse(exception1.getMessage().equals(exception2.getMessage()));
        assertEquals("User is not found: user1", exception1.getMessage());
        assertEquals("User is not found: user2", exception2.getMessage());
    }

        // Test that getMessage returns the same value consistently
        String message = "Consistent message";
        UnsupportedSearchException exception = new UnsupportedSearchException(message);

        String firstCall = exception.getMessage();
        String secondCall = exception.getMessage();
        String thirdCall = exception.getMessage();

        assertEquals(firstCall, secondCall);

        assertEquals("Type1", exception1.getType());
        assertEquals("Message1", exception1.getMessage());
        assertEquals("Type2", exception2.getType());
        assertEquals("Message2", exception2.getMessage());

        assertNotSame(exception1, exception2);
    }

    @Test
    public void test_serialVersionUID() {

        LdapConfigurationException exception3 = new LdapConfigurationException("Error 3");

        assertEquals("Error 1", exception1.getMessage());
        assertEquals("Error 2", exception2.getMessage());
        assertEquals("Error 3", exception3.getMessage());

        // Ensure they are different instances
        assertNotSame(exception1, exception2);
        assertNotSame(exception2, exception3);

        assertEquals("service1 is not available.", exception1.getMessage());

        ContainerNotAvailableException exception2 = new ContainerNotAvailableException("service2", new RuntimeException());
        assertEquals("service2 is not available.", exception2.getMessage());

        ContainerNotAvailableException exception3 = new ContainerNotAvailableException(new RuntimeException());

        assertEquals("Top level error", exception.getMessage());
        assertEquals(middleCause, exception.getCause());
        assertEquals("Middle cause", exception.getCause().getMessage());
        assertEquals(rootCause, exception.getCause().getCause());
        assertEquals("Root cause", exception.getCause().getCause().getMessage());
    }

    @Test
    public void test_throwAndCatch() {

        assertEquals("Level 3", level3.getMessage());
        assertEquals(level2, level3.getCause());
        assertEquals("Level 2", level3.getCause().getMessage());
        assertEquals(level1, level3.getCause().getCause());
        assertEquals("Level 1", level3.getCause().getCause().getMessage());
    }

    @Test
    public void test_throwAndCatchException() {

        assertTrue(exception instanceof FessSystemException);
    }

    @Test
    public void test_constructorWithNullMessage() {
        // Test constructor with null message
        SearchQueryException exception = new SearchQueryException((String) null);

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

        ThemeException exception = new ThemeException(message, cause);

        assertNotNull(exception);
        assertEquals(message, exception.getMessage());
        assertEquals(cause, exception.getCause());
        assertEquals("Config file not found", exception.getCause().getMessage());
    }

    @Test
    public void test_constructorWithNullMessage() {
        // Test constructor with null message

        assertEquals("Top level error", exception.getMessage());
        assertEquals(intermediateCause, exception.getCause());
        assertEquals("Intermediate cause", exception.getCause().getMessage());
        assertEquals(rootCause, exception.getCause().getCause());
        assertEquals("Root cause", exception.getCause().getCause().getMessage());
    }

    @Test
    public void test_withLongMessage() {