* @return order ID.
* @throws IOException
*/
public BTCChinaIntegerResponse buy(BigDecimal price, BigDecimal amount, String market) throws IOException {
BTCChinaBuyOrderRequest request = new BTCChinaBuyOrderRequest(price, amount, market);
final BTCChinaIntegerResponse response;
try {
response = btcChina.buyOrder2(signatureCreator, BTCChinaUtils.getNonce(), request);
} catch (HttpStatusIOException e) {
if (e.getHttpStatusCode() == 401) {