docs: public String placeGateioLimitOrder(
        CurrencyPair currencyPair, GateioOrderType orderType, BigDecimal rate, BigDecimal amount)
        throws IOException {
  
      String pair = formatCurrencyPair(currencyPair);
  
      GateioPlaceOrderReturn orderId;
      if (orderType.equals(GateioOrderType.BUY)) {
        orderId = bter.buy(pair, rate, amount, apiKey, signatureCreator);
      } else {
        orderId = bter.sell(pair, rate, amount, apiKey, signatureCreator);
      }
  
      return handleResponse(orderId).getOrderId();
    }