code: func (ref *EventClientRef) RegisterTxStatusEvent(txID string) (fab.Registration, <-chan *fab.TxStatusEvent, error) {
  	service, err := ref.get()
  	if err != nil {
  		return nil, nil, err
  	}
  	return service.RegisterTxStatusEvent(txID)
  }
docs: // RegisterTxStatusEvent registers for transaction status events.