def filter_objects_by_section(self, rels, section):
        """Build a queryset containing all objects in the section subtree."""

        subtree = section.get_descendants(include_self=True)
        kwargs_list = [{'%s__in' % rel.field.name: subtree} for rel in rels]
        q = Q(**kwargs_list[0])
        for kwargs in kwargs_list[1:]:
            q |= Q(**kwargs)
        return self.get_manager(get_item_model_class()).filter(q).distinct()
Build a queryset containing all objects in the section subtree.