@Override
 protected void buildMessage(
     final FudgeSerializer serializer, final MutableFudgeMsg message, final FXMatrix object) {
   final Map<Currency, Integer> currencies = object.getCurrencies();
   for (final Map.Entry<Currency, Integer> entry : currencies.entrySet()) {
     message.add(CURRENCY_FIELD, entry.getKey().getCode());
     message.add(ORDER_FIELD, entry.getValue());
   }
   final double[][] rates = object.getRates();
   for (final double[] array : rates) {
     message.add(ENTRIES_FIELD, array.length);
     final MutableFudgeMsg msg = serializer.newMessage();
     serializer.addToMessageWithClassHeaders(msg, ROW_FIELD, null, array);
     message.add(FX_RATES_FIELD, msg);
   }
 }