code: func (p *Mx) Consume() (*proto.Message, error) {
  	select {
  	case <-p.stop:
  		return nil, ErrMxClosed
  	case msg := <-p.msgc:
  		return msg, nil
  	case err := <-p.errc:
  		return nil, err
  	}
  }
docs: // Consume returns Consume result from any of the merged consumer.