docs: def reqRealTimeBars(
              self, contract: Contract, barSize: int,
              whatToShow: str, useRTH: bool,
              realTimeBarsOptions: List[TagValue] = None) -> RealTimeBarList:
          """
          Request realtime 5 second bars.
  
          https://interactivebrokers.github.io/tws-api/realtime_bars.html
  
          Args:
              contract: Contract of interest.
              barSize: Must be 5.
              whatToShow: Specifies the source for constructing bars.
                  Can be 'TRADES', 'MIDPOINT', 'BID' or 'ASK'.
              useRTH: If True then only show data from within Regular
                  Trading Hours, if False then show all data.
              realTimeBarsOptions: Unknown.
          """
          reqId = self.client.getReqId()
          bars = RealTimeBarList()
          bars.reqId = reqId
          bars.contract = contract
          bars.barSize = barSize
          bars.whatToShow = whatToShow
          bars.useRTH = useRTH
          bars.realTimeBarsOptions = realTimeBarsOptions
          self.wrapper.startSubscription(reqId, bars, contract)
          self.client.reqRealTimeBars(
              reqId, contract, barSize, whatToShow, useRTH, realTimeBarsOptions)
          return bars