if link_name is None:
            return {"url": None, "error": "Link name not passed"}, 400
        ti = session.scalar(
            select(TaskInstance)
            .filter_by(dag_id=dag_id, task_id=task_id, execution_date=dttm, map_index=map_index)
            .options(joinedload(TaskInstance.dag_run))
            .limit(1)
        )
        if not ti:
            return {"url": None, "error": "Task Instances not found"}, 404
        try:
            url = task.get_extra_links(ti, link_name)
        except ValueError as err:
            return {"url": None, "error": str(err)}, 404
        if url:
            return {"error": None, "url": url}
        else:
            return {"url": None, "error": f"No URL found for {link_name}"}, 404
    @expose("/object/graph_data")
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_INSTANCE),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_TASK_LOG),
        ]
    )
    @gzipped
    @action_logging
    @provide_session
    def graph_data(self, session: Session = NEW_SESSION):