code: def get(app: web.Application,
          feature_type: Type[Any] = None,
          key: Hashable = None
          ) -> Any:
      
      key = key or feature_type
  
      if not key:
          raise AssertionError('No feature identifier provided')
  
      try:
          found = app[FEATURES_KEY][key]
      except KeyError:
          raise KeyError(f'No feature found for "{key}"')
  
      if feature_type and not isinstance(found, feature_type):
          raise AssertionError(f'Found {found} did not match type "{feature_type}"')
  
      return found
docs: Finds declared feature.
      Identification is done based on feature type and key.
  
      Args:
          app (web.Application):
              The current Aiohttp application.
  
          feature_type (Type[Any]):
              The Python type of the desired feature.
              If specified, it will be checked against the found feature.
  
          key (Hashable):
              A specific identifier for the desired feature.
              Defaults to `feature_type`
  
      Returns:
          Any: The feature found for the combination of `feature_type` and `key`