code: public OkCoinFutureComment getFutureEstimatedPrice(CurrencyPair currencyPair) throws IOException {
      return okCoin.getFutureEstimatedPrice("1", OkCoinAdapters.adaptSymbol(currencyPair));
    }
docs: 获取交割预估价
  
  @param currencyPair
  @return
  @throws IOException