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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def item_from_event(self, domain_event_or_events):
 """ Maps domain event to sequenced item namedtuple. :param domain_event_or_events: application-level object (or list) :return: namedtuple: sequence item namedtuple (or list) """

        # 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)