func TestPull(t *testing.T){

	client := pubsubclient.GetPubSubClient()
	ctx := context.Background()

	mu := sync.Mutex{}
	count := 0

	waitAndAck := func(msg *pubsub.Message) {
		time.Sleep(10 * time.Second)
		msg.Ack()
		mu.Lock()
		defer mu.Unlock()
		count--
		logrus.Println("count-- :", count)
	}

	sub := client.Subscription("testtoppicsubs")
	sub.ReceiveSettings.NumGoroutines = 1
	sub.ReceiveSettings.MaxOutstandingMessages = 10
	err := sub.Receive(ctx, func(ctx context.Context, msg *pubsub.Message) {
		fmt.Printf("Got message: %q\n", string(msg.Data))
		mu.Lock()
		count++
		logrus.Println("count++ :", count) //shouldn't go beyond 10.
		mu.Unlock()
		go waitAndAck(msg)
	})

	if err != nil {
		t.Log("Error : ",err)
	}

}