Configure stepper motor prior to operation.
        This is a FirmataPlus feature.

        :param steps_per_revolution: number of steps per motor revolution

        :param stepper_pins: a list of control pin numbers - either 4 or 2

        :returns: No return value.

async def stepper_config(self, steps_per_revolution, stepper_pins):
        """
        Configure stepper motor prior to operation.
        This is a FirmataPlus feature.

        :param steps_per_revolution: number of steps per motor revolution

        :param stepper_pins: a list of control pin numbers - either 4 or 2

        :returns: No return value.
        """
        data = [PrivateConstants.STEPPER_CONFIGURE, steps_per_revolution & 0x7f,
                (steps_per_revolution >> 7) & 0x7f]
        for pin in range(len(stepper_pins)):
            data.append(stepper_pins[pin])
        await self._send_sysex(PrivateConstants.STEPPER_DATA, data)