Switch lights off. If group (1-4) is not specified,
            all four groups will be switched off.

def off(self, group=None):
        """ Switch lights off. If group (1-4) is not specified,
            all four groups will be switched off. """
        if group is None or group == 0:
            self._send_to_group(group, send_on=False, command="all_off")
            return
        self._send_to_group(group, per_group=True, send_on=False, rgbw_cmd=self.RGBW_GROUP_X_OFF, white_cmd=self.WHITE_GROUP_X_OFF)