async def query_power_state(self):
        """
        Query the machine's BMC for the current power state.

        :returns: Current power state.
        :rtype: `PowerState`
        """
        power_data = await self._handler.query_power_state(
            system_id=self.system_id)
        # Update the internal state of this object as well, since we have the
        # updated power state from the BMC directly. MAAS server does this as
        # well, just do it client side to make it nice for a developer.
        self._data['power_state'] = power_data['state']
        return PowerState(power_data['state'])
Query the machine's BMC for the current power state.

        :returns: Current power state.
        :rtype: `PowerState`