code: def first_seen(self, first_seen):
          
          if not self.can_update():
              self._tcex.handle_error(910, [self.type])
  
          first_seen = self._utils.format_datetime(first_seen, date_format='%Y-%m-%dT%H:%M:%SZ')
          self._data['firstSeen'] = first_seen
          request = {'firstSeen': first_seen}
          return self.tc_requests.update(self.api_type, self.api_sub_type, self.unique_id, request)
docs: Updates the campaign with the new first_seen date.
  
          Args:
              first_seen: The first_seen date. Converted to %Y-%m-%dT%H:%M:%SZ date format
  
          Returns: