Turn on or off flashing of the device's LED for physical
        identification purposes.

def flash(self, flash=True):
        """
        Turn on or off flashing of the device's LED for physical
        identification purposes.
        """
        if flash:
            action = canstat.kvLED_ACTION_ALL_LEDS_ON
        else:
            action = canstat.kvLED_ACTION_ALL_LEDS_OFF

        try:
            kvFlashLeds(self._read_handle, action, 30000)
        except (CANLIBError, NotImplementedError) as e:
            log.error('Could not flash LEDs (%s)', e)