Unsubscribe from realtime streaming tick data.

        Args:
            contract: The exact contract object that was used to
                subscribe with.

def cancelMktData(self, contract: Contract):
        """
        Unsubscribe from realtime streaming tick data.

        Args:
            contract: The exact contract object that was used to
                subscribe with.
        """
        ticker = self.ticker(contract)
        reqId = self.wrapper.endTicker(ticker, 'mktData')
        if reqId:
            self.client.cancelMktData(reqId)
        else:
            self._logger.error(
                'cancelMktData: ' f'No reqId found for contract {contract}')