code: public OkCoinFuturesUserInfoFixed getFuturesUserInfoFixed() throws IOException {
  
      OkCoinFuturesUserInfoFixed okCoinFuturesUserInfoFixed =
          okCoin.getFuturesUserInfoFixed(apikey, signatureCreator());
  
      return returnOrThrow(okCoinFuturesUserInfoFixed);
    }
docs: 获取逐仓合约账户信息（逐仓）
  
  @return
  @throws IOException