code: @Override
    public Guid guid() throws IOException {
      StringBuilder uniqueString = new StringBuilder();
      uniqueString.append(getFileStatus().getModificationTime());
      uniqueString.append(getFileStatus().getLen());
      uniqueString.append(getFileStatus().getPath());
      return Guid.fromStrings(uniqueString.toString());
    }
docs: Generates a replicable guid to uniquely identify the origin of this {@link CopyableFile}.
  @return a guid uniquely identifying the origin file.