code: func SetTransactionID(poolName string, oldID uint64, newID uint64) error {
  	task, err := TaskCreateNamed(deviceTargetMsg, poolName)
  	if task == nil {
  		return err
  	}
  
  	if err := task.setSector(0); err != nil {
  		return fmt.Errorf("devicemapper: Can't set sector %s", err)
  	}
  
  	if err := task.setMessage(fmt.Sprintf("set_transaction_id %d %d", oldID, newID)); err != nil {
  		return fmt.Errorf("devicemapper: Can't set message %s", err)
  	}
  
  	if err := task.run(); err != nil {
  		return fmt.Errorf("devicemapper: Error running SetTransactionID %s", err)
  	}
  	return nil
  }
docs: // SetTransactionID sets a transaction id for the specified device name.