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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 _startup(cls):
 """ Create Endpoint instances and manage automatic flags. """

        for endpoint_name in sorted(hookenv.relation_types()):
            # populate context based on attached relations
            relf = relation_factory(endpoint_name)
            if not relf or not issubclass(relf, cls):
                continue

            rids = sorted(hookenv.relation_ids(endpoint_name))
            # ensure that relation IDs have the endpoint name prefix, in case
            # juju decides to drop it at some point
            rids = ['{}:{}'.format(endpoint_name, rid) if ':' not in rid
                    else rid for rid in rids]
            endpoint = relf(endpoint_name, rids)
            cls._endpoints[endpoint_name] = endpoint
            endpoint.register_triggers()
            endpoint._manage_departed()
            endpoint._manage_flags()
            for relation in endpoint.relations:
                hookenv.atexit(relation._flush_data)