func (w *Worker) Login(from *ip.IP, user *user.User) error { if from.IsBlacklisted() || user.IsBlacklisted() { return w.LoginWithBlocked(from, user) } n := rand.Intn(10) if n < 6 && from.D()%3 == 0 { return w.LoginWithSuccess(from, user) } else { return w.LoginWithFail(from, user) } }