code: func checkIndexConsistency(fs []FileInfo) error {
  	for _, f := range fs {
  		if err := checkFileInfoConsistency(f); err != nil {
  			return fmt.Errorf("%q: %v", f.Name, err)
  		}
  	}
  	return nil
  }
docs: // checkIndexConsistency verifies a number of invariants on FileInfos received in
  // index messages.