code: func MaxReceiveMessages(max int64) broker.SubscribeOption {
  	return func(o *broker.SubscribeOptions) {
  		if o.Context == nil {
  			o.Context = context.Background()
  		}
  		o.Context = context.WithValue(o.Context, maxMessagesKey{}, max)
  	}
  }
docs: // MaxReceiveMessages indicates how many messages a receive operation should pull
  // during any single call