code: func (b *sqsBroker) Subscribe(queueName string, h broker.Handler, opts ...broker.SubscribeOption) (broker.Subscriber, error) {
  	queueURL, err := b.urlFromQueueName(queueName)
  	if err != nil {
  		return nil, err
  	}
  
  	options := broker.SubscribeOptions{
  		AutoAck: true,
  		Queue:   queueName,
  		Context: context.Background(),
  	}
  
  	for _, o := range opts {
  		o(&options)
  	}
  
  	subscriber := &subscriber{
  		options:   options,
  		URL:       queueURL,
  		queueName: queueName,
  		svc:       b.svc,
  		exit:      make(chan bool),
  	}
  	go subscriber.run(h)
  
  	return subscriber, nil
  }
docs: // Subscribe subscribes to an SQS queue, starting a goroutine to poll for messages