docs: public static File writeObjectToTempFile(Object o, String filename)
    throws IOException {
      File file = File.createTempFile(filename, ".tmp");
      file.deleteOnExit();
      ObjectOutputStream oos = new ObjectOutputStream(new BufferedOutputStream(
          new GZIPOutputStream(new FileOutputStream(file))));
      oos.writeObject(o);
      oos.close();
      return file;
    }