sclass SSIListFrame > MetaWithChangeListeners is ByteIO {
  settable int magicMarker = 0xFFFFBABE;
  settableWithVar long timestampInMS;
  settableWithVar new SSIList content;
  
  public void readWrite(ByteHead head) {
    head.exchangeInt(magicMarker);
    head.exchangeLong(varTimestampInMS());
    head.exchange(content);
  }
}