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

    public void test_constructor_withSpecialCharacters() {
        // Test with special characters in message
        String message = "Search not supported: \n\t!@#$%^&*(){}[]|\\:;\"'<>,.?/~`";

        assertNotNull(exception);
        assertEquals("User is not found: null", exception.getMessage());
        assertNull(exception.getCause());
    }

    public void test_constructor_withSpecialCharacters() {
        // Test with username containing special characters
        String username = "******@****.***";
        FessUserNotFoundException exception = new FessUserNotFoundException(username);

        assertNotNull(exception);
        assertEquals("Not Found:  Parent: ", exception.getMessage());
        assertNull(exception.getCause());
    }

    public void test_constructor_withSpecialCharacters() {
        // Test with URLs containing special characters
        String parentUrl = "http://example.com/parent?query=test&id=123";
        String url = "http://example.com/child#fragment";

        assertNull(param.getValues()[1]);
        assertEquals("value3", param.getValues()[2]);
        assertNull(param.getValues()[3]);
    }

    public void test_constructor_withSpecialCharacters() {
        // Test with special characters in name and values
        String name = "param-name_123!@#";
        String[] values = { "value with spaces", "value@special#chars", "日本語" };