code: func ListFilesToTruncate(fs fs.FileSystem, injections api.VolumeList) ([]string, error) {
  	result := []string{}
  	for _, s := range injections {
  		if s.Keep {
  			continue
  		}
  		files, err := ListFiles(fs, s)
  		if err != nil {
  			return nil, err
  		}
  		result = append(result, files...)
  	}
  	return result, nil
  }
docs: // ListFilesToTruncate returns a flat list of all files that are injected into a
  // container which need to be truncated. All files from nested directories are returned in the list.