assertNull(user.getPostalCode());

        user.setPostalCode("12345");
        assertEquals("12345", user.getPostalCode());
    }

    @Test
    public void test_user_carLicense() {
        final User user = new User();
        assertNull(user.getCarLicense());

        user.setCarLicense("ABC123");
        assertEquals("ABC123", user.getCarLicense());
    }

    @Test