holds latest tick bid/ask/last price

def handleTickGeneric(self, msg):
        """
        holds latest tick bid/ask/last price
        """

        df2use = self.marketData
        if self.contracts[msg.tickerId].m_secType in ("OPT", "FOP"):
            df2use = self.optionsData

        # create tick holder for ticker
        if msg.tickerId not in df2use.keys():
            df2use[msg.tickerId] = df2use[0].copy()

        if msg.tickType == dataTypes["FIELD_OPTION_IMPLIED_VOL"]:
            df2use[msg.tickerId]['iv'] = round(float(msg.value), 2)

        # elif msg.tickType == dataTypes["FIELD_OPTION_HISTORICAL_VOL"]:
        #     df2use[msg.tickerId]['historical_iv'] = round(float(msg.value), 2)

        # fire callback
        self.ibCallback(caller="handleTickGeneric", msg=msg)