void readWrite(SomethingHead head);

default byte[] saveToByteArray aka saveAsByteArray aka toByteArray(SomethingHead head default new) {

  var baos = byteArrayOutputStream();

  head.outputStream(baos);

  readWrite(head);

  head.finish();

  ret baos.toByteArray();

}

default S toHexString() {

  ret main toHexString(toByteArray());

}

default File saveToFile(File file) {

  temp OutputStream out = bufferedFileOutputStream(file);

  var head = new SomethingHead(out);

  readWrite(head);

  head.finish();

  ret file;

}

default selfType load aka fromByteArray(byte[] data) {

  readWrite(new SomethingHead(new ByteArrayInputStream(data)));

  this;

}

default selfType load(File file) {

  temp InputStream in = bufferedInputStream(file);

  readWrite(new SomethingHead(in));

  this;

}

default long byteIOLength() {

  new JustCountingOutputStream out;

  var head = new SomethingHead(out);

  readWrite(head);

  head.finish();

  ret out!;

}