assertEquals(level1, topLevel.getCause());
        assertEquals("Level 1: Authentication service error", topLevel.getCause().getMessage());
        assertEquals(level2, topLevel.getCause().getCause());
        assertEquals("Level 2: User lookup failed", topLevel.getCause().getCause().getMessage());
        assertEquals(level3, topLevel.getCause().getCause().getCause());

        assertEquals("Top level", topException.getMessage());
        assertEquals(middleCause, topException.getCause());
        assertEquals(rootCause, topException.getCause().getCause());
    }

    public void test_serialVersionUID() {
        // Test that serialVersionUID is properly defined

        // Verify cause chain is preserved
        assertEquals(middleCause, exception.getCause());
        assertEquals(rootCause, exception.getCause().getCause());
    }

    public void test_emptyMessage() {
        // Setup
        final String message = "";

        } catch (RuntimeException e) {
            assertEquals("Wrapper exception", e.getMessage());
            assertNotNull(e.getCause());
            assertTrue(e.getCause() instanceof FessUserNotFoundException);
            assertEquals("User is not found: testuser", e.getCause().getMessage());
        }
    }

    public void test_multipleInstances() {
        // Test that multiple instances are independent

        final SsoMessageException exception = new SsoMessageException(messageCode, message, middleCause);

        // Verify cause chain
        assertEquals(middleCause, exception.getCause());
        assertEquals(rootCause, exception.getCause().getCause());
    }

    public void test_emptyMessage() {
        // Setup
        final String 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());
    }

    public void test_withLongMessage() {
        // Test with a very long message

        assertEquals("Theme operation failed", exception.getMessage());
        assertNotNull(exception.getCause());
        assertEquals(middleCause, exception.getCause());
        assertEquals("Processing failed", exception.getCause().getMessage());

        // Check nested cause
        Throwable nestedCause = exception.getCause().getCause();
        assertNotNull(nestedCause);
        assertEquals(innerCause, nestedCause);

        assertEquals("LDAP operation failed", exception.getMessage());
        assertEquals(middleCause, exception.getCause());
        assertEquals("LDAP configuration error", exception.getCause().getMessage());
        assertEquals(innerCause, exception.getCause().getCause());
        assertEquals("Invalid LDAP parameter", exception.getCause().getCause().getMessage());
    }

    public void test_throwAndCatch() {

        assertNotNull(exception);
        assertEquals(message, exception.getMessage());
        assertEquals(intermediateCause, exception.getCause());
        assertEquals(rootCause, exception.getCause().getCause());
    }

    public void test_constructor_withSpecialCharactersInMessage() {
        // Test constructor with special characters in message

        InvalidAccessTokenException exception = new InvalidAccessTokenException(type, message);

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

    public void test_constructor_withNullType() {
        // Test constructor with null type
        String type = null;
        String message = "Token validation failed";