code: func moveFiles(files map[string]string) error {
  	filesToRecover := map[string]string{}
  	for from, to := range files {
  		if err := os.Rename(from, to); err != nil {
  			return rollbackFiles(filesToRecover, err)
  		}
  		filesToRecover[to] = from
  	}
  	return nil
  }
docs: // moveFiles moves files from one directory to another.