code: func (op *PortAllocationOperation) Rollback() []error {
  	if op.dryRun {
  		return nil
  	}
  
  	errors := []error{}
  
  	for _, allocated := range op.allocated {
  		err := op.pa.Release(allocated)
  		if err != nil {
  			errors = append(errors, err)
  		}
  	}
  
  	if len(errors) == 0 {
  		return nil
  	}
  	return errors
  }
docs: // (Try to) undo any operations we did