code: def event_from_item(self, sequenced_item):
          
          assert isinstance(sequenced_item, self.sequenced_item_class), (
              self.sequenced_item_class, type(sequenced_item)
          )
  
          # Get the topic and state.
          topic = getattr(sequenced_item, self.field_names.topic)
          state = getattr(sequenced_item, self.field_names.state)
  
          return self.event_from_topic_and_state(topic, state)
docs: Reconstructs domain event from stored event topic and
          event attrs. Used in the event store when getting domain events.