code: def peek_record(self, model_class, record_id):
          
          if self._cache:
              return self._cache.get_record(model_class.__name__, record_id)
          else:
              return None
docs: Return an instance of the model_class from the cache if it is present.
  
          Args:
              model_class (:class:`cinder_data.model.CinderModel`): A subclass of
                  :class:`cinder_data.model.CinderModel` of your chosen model.
              record_id (int): The id of the record requested.
  
          Returns:
              :class:`cinder_data.model.CinderModel`: An instance of model_class or None.