@Test
public void testJsonsMapping() {

    mapper = new JSONExpressionUserMapper(attributeMappings);
    User user = new User();
    attributeMappings.put("transformed", "email");
    mapper.mapUser(SAMPLE_JSON, user);
    
    assertEquals(1, user.getAttribute().size());
    assertEquals("transformed", user.getAttribute().get(0).getName());
    assertEquals("myemail@email.com", user.getAttribute().get(0).getValue());
}