'Retrieve latest state.'

@asyncio.coroutine
def async_update(self):

    _LOGGER.debug('Updating    User    sensor:    %s', self._sensor)
    if ('current' in self._sensor):
        self._state = self._usrobj.current_sleep_score
        self._attr = self._usrobj.current_values
    elif ('last' in self._sensor):
        self._state = self._usrobj.last_sleep_score
        self._attr = self._usrobj.last_values
    elif ('bed_temp' in self._sensor):
        temp = self._usrobj.current_values['bed_temp']
        if (self._units == 'si'):
            self._state = round(temp, 2)
        else:
            self._state = round(((temp * 1.8) + 32), 2)
    elif ('sleep_stage' in self._sensor):
        self._state = self._usrobj.current_values['stage']
