@Test
public void updateUserTest() {

    //Setup:
    Response response = target().path("users/" + UsernameTestFilter.USERNAME)
            .request().put(Entity.entity(groupedModelToString(user.getModel(), getRDFFormat("jsonld"), transformer),
                    MediaType.APPLICATION_JSON_TYPE));
    assertEquals(response.getStatus(), 200);
    verify(engineManager, atLeastOnce()).retrieveUser(ENGINE_NAME, UsernameTestFilter.USERNAME);
    verify(engineManager).updateUser(eq(ENGINE_NAME), any(User.class));
}