code: private void writeObject(ObjectOutputStream stream)
           throws IOException
      {
          maxIntegerDigits = (maximumIntegerDigits > Byte.MAX_VALUE) ? Byte.MAX_VALUE :
              (byte)maximumIntegerDigits;
          minIntegerDigits = (minimumIntegerDigits > Byte.MAX_VALUE) ? Byte.MAX_VALUE :
              (byte)minimumIntegerDigits;
          maxFractionDigits = (maximumFractionDigits > Byte.MAX_VALUE) ? Byte.MAX_VALUE :
              (byte)maximumFractionDigits;
          minFractionDigits = (minimumFractionDigits > Byte.MAX_VALUE) ? Byte.MAX_VALUE :
              (byte)minimumFractionDigits;
          stream.defaultWriteObject();
      }
docs: Write out the default serializable data, after first setting
  the <code>byte</code> fields such as <code>maxIntegerDigits</code> to be
  equal to the <code>int</code> fields such as <code>maximumIntegerDigits</code>
  (or to <code>Byte.MAX_VALUE</code>, whichever is smaller), for compatibility
  with the JDK 1.1 version of the stream format.