select {
		case <-wg.C():
			return
		case <-time.After(time.Second):
			t.Fatal("Wait group timed out!\n")
		}
	}
}

func (wg *WaitGroup) Add(i int32) {
	select {
	case <-wg.done:
		panic("use of an already closed WaitGroup")
	default:
	}
	atomic.AddInt32(&wg.count, i)
}

func (wg *WaitGroup) Done() {
	i := atomic.AddInt32(&wg.count, -1)
	if i == 0 {
		close(wg.done)
	}
}