docs: async def observation(self):
          """Retrieve current weather observation."""
  
          try:
              observations = await self.api.observations()
          except:
              return self._last_observation
  
          closest = self._filter_closest(self.station.latitude,
                                         self.station.longitude,
                                         observations)
  
          if closest is not None:
              self._last_observation = closest.currentObs
               
          return self._last_observation