def _call_service(self, service_name, service_data=None,
                      allow_override=False):
        """Call either a specified or active child's service."""
        if allow_override and service_name in self._cmds:
            call_from_config(
                self.hass, self._cmds[service_name], blocking=True)
            return

        if service_data is None:
            service_data = {}

        active_child = self._child_state
        service_data[ATTR_ENTITY_ID] = active_child.entity_id

        self.hass.services.call(DOMAIN, service_name, service_data,
                                blocking=True)
dataset/ETHPy150Open home-assistant/home-assistant/homeassistant/components/media_player/universal.py/UniversalMediaPlayer._call_service/original