if f.nextErr != nil {
		return nil, f.nextErr
	}

	if req.GetVolumeId() == "" {
		return nil, errors.New("missing volume id")
	}
	if req.GetTargetPath() == "" {
		return nil, errors.New("missing target path")
	}
	delete(f.nodePublishedVolumes, req.GetVolumeId())

	// "The SP MUST delete the file or directory it created at this path."