def _migrate_event_persons_links(self):
        person_link_map = {}
        for chair in getattr(self.old_event, '_chairs', []):
            person = self._get_person(chair)
            if not person:
                continue
            link = person_link_map.get(person)
            if link:
                self.importer.print_warning(
                    cformat('%{yellow!}Duplicated chair "{}" for event').format(person.full_name),
                    event_id=self.event.id
                )
            else:
                link = EventPersonLink(person=person, **self._get_person_data(chair))
                person_link_map[person] = link
                self.event.person_links.append(link)