docs: def _serialize_data(self, data):
          """Return serialized data or list of ids, depending on `hydrate_data` query param."""
          if self.request and self.request.query_params.get('hydrate_data', False):
              serializer = DataSerializer(data, many=True, read_only=True)
              serializer.bind('data', self)
              return serializer.data
          else:
              return [d.id for d in data]