code: def reqSecDefOptParams(
              self, underlyingSymbol: str,
              futFopExchange: str, underlyingSecType: str,
              underlyingConId: int) -> List[OptionChain]:
          
          return self._run(
              self.reqSecDefOptParamsAsync(
                  underlyingSymbol, futFopExchange,
                  underlyingSecType, underlyingConId))
docs: Get the option chain.
  
          This method is blocking.
  
          https://interactivebrokers.github.io/tws-api/options.html
  
          Args:
              underlyingSymbol: Symbol of underlier contract.
              futFopExchange: Exchange (only for ``FuturesOption``, otherwise
                  leave blank).
              underlyingSecType: The type of the underlying security, like
                  'STK' or 'FUT'.
              underlyingConId: conId of the underlying contract.