public void it_should_return_no_trips_if_users_are_not_friends()
{
Assert.That(_tripService.GetFriendsTrips(_anotherUser, _user), Is.Empty);
}
public void it_should_throw_a_user_not_logged_on_exception()
{
var tripService = new TripService(new StubTripDao());
Assert.That(() => tripService.GetFriendsTrips(AnotherUser, NotLoggedInUser), Throws.TypeOf <UserNotLoggedInException>());
}