code: void write(File f) throws FileNotFoundException, IOException {
  		try (ObjectOutputStream os = new ObjectOutputStream(new FileOutputStream(f))) {
  			os.writeObject(this);
  		}
  	}
docs: Writes the configuration to file.
  @param f the file
  @throws FileNotFoundException if the file does not exist, is a directory rather
  than a regular file, or for some other reason cannot be opened for reading.
  @throws IOException if an I/O problem occurs.