code: func (el *ChannelEventListener) RegPromotions() *ChannelEventListener {
  	el.Promoted = make(chan *promoter.PromotionReattachmentEvent)
  	el.ids = append(el.ids, el.em.RegisterListener(func(data interface{}) {
  		el.Promoted <- data.(*promoter.PromotionReattachmentEvent)
  	}, promoter.EventPromotion))
  	return el
  }
docs: // RegPromotions registers this listener to listen for promotions.