@callback
def _async_set_unavailable(self, now):
    'Set state to UNAVAILABLE.'
    self._remove_unavailability_tracker = None
    self._is_available = False
    self.async_schedule_update_ha_state()
Set state to UNAVAILABLE.
@callback
def _async_set_unavailable(self, now):
    
    self._remove_unavailability_tracker = None
    self._is_available = False
    self.async_schedule_update_ha_state()