login_should_not_populate_http_session_if_unsuccessfull() {
// Absent user
Optional<User> absentUser = Optional.absent();
// Create UserService partial mock
UserService service = mock(UserService.class);
when(service.login("user", "password")).thenReturn(absentUser);
UserREST userREST = new UserREST(null, null, null, service, null, null, null);
SessionHelper sessionHelper = mock(SessionHelper.class);
LoginRequest req = new LoginRequest();