Get the datetime of earliest available historical data
        for the contract.

        Args:
            contract: Contract of interest.
            useRTH: If True then only show data from within Regular
                Trading Hours, if False then show all data.
            formatDate: If set to 2 then the result is returned as a
                timezone-aware datetime.datetime with UTC timezone.

def reqHeadTimeStamp(
            self, contract: Contract, whatToShow: str,
            useRTH: bool, formatDate: int = 1) -> datetime.datetime:
        """
        Get the datetime of earliest available historical data
        for the contract.

        Args:
            contract: Contract of interest.
            useRTH: If True then only show data from within Regular
                Trading Hours, if False then show all data.
            formatDate: If set to 2 then the result is returned as a
                timezone-aware datetime.datetime with UTC timezone.
        """
        return self._run(
            self.reqHeadTimeStampAsync(
                contract, whatToShow, useRTH, formatDate))