code: func (ref *EventClientRef) RegisterChaincodeEvent(ccID, eventFilter string) (fab.Registration, <-chan *fab.CCEvent, error) {
  	service, err := ref.get()
  	if err != nil {
  		return nil, nil, err
  	}
  	return service.RegisterChaincodeEvent(ccID, eventFilter)
  }
docs: // RegisterChaincodeEvent registers for chaincode events.