docs: public static String makeMercadoBitcoinOrderId(CurrencyPair currencyPair, String orderId) {
  
      String pair;
  
      if (currencyPair.equals(CurrencyPair.BTC_BRL)) {
        pair = "btc_brl";
      } else if (currencyPair.equals(new CurrencyPair(Currency.LTC, Currency.BRL))) {
        pair = "ltc_brl";
      } else {
        throw new NotAvailableFromExchangeException();
      }
  
      return pair + ":" + orderId;
    }