code: def item_from_event(self, domain_event_or_events):
          
          # Convert the domain event(s) to sequenced item(s).
          if isinstance(domain_event_or_events, (list, tuple)):
              return [self.item_from_event(e) for e in domain_event_or_events]
          else:
              return self.mapper.item_from_event(domain_event_or_events)
docs: Maps domain event to sequenced item namedtuple.
  
          :param domain_event_or_events: application-level object (or list)
          :return: namedtuple: sequence item namedtuple (or list)