threadConsumer1 = threading.Thread(target=a, args=(1,))
    threadConsumer1.start()

    threadConsumer2 = threading.Thread(target=a, args=(2,))
    threadConsumer2.start()

    # threadConsumer3 = threading.Thread(target=a, args=(3,))
    # threadConsumer3.start()

    threadConsumer1.join()
    threadConsumer2.join()
    # threadConsumer3.join()