code: public CoinbaseOrder getCoinbaseOrder(String orderIdOrCustom) throws IOException {
  
      final CoinbaseOrder order =
          coinbase.getOrder(
              orderIdOrCustom,
              exchange.getExchangeSpecification().getApiKey(),
              signatureCreator,
              exchange.getNonceFactory());
      return handleResponse(order);
    }
docs: Authenticated resource which returns order details for a specific order id or merchant custom.
  
  @param orderIdOrCustom
  @return
  @throws IOException
  @see <a
  href="https://coinbase.com/api/doc/1.0/orders/show.html">coinbase.com/api/doc/1.0/orders/show.html</a>