https://github.com/apache/airflow/blob/main/airflow/cli/commands/task_command.py#L145
"""Return grid data."""
        dag_id = request.args.get("dag_id")
        dag = get_airflow_app().dag_bag.get_dag(dag_id)
        if not dag:
            return {"error": f"can't find dag {dag_id}"}, 404
        root = request.args.get("root")
        if root:
            filter_upstream = request.args.get("filter_upstream") == "true"
            filter_downstream = request.args.get("filter_downstream") == "true"
            dag = dag.partial_subset(
                task_ids_or_regex=root, include_upstream=filter_upstream, include_downstream=filter_downstream
            )
        num_runs = request.args.get("num_runs", type=int)
        if num_runs is None: