https://github.com/apache/airflow/blob/main/airflow/cli/commands/task_command.py#L145
child_instances = [
                item
                for sublist in (child["instances"] for child in children if "instances" in child)
                for item in sublist
                if item["run_id"] == dag_run.run_id
                if item
            ]
            children_queued_dttms = (item["queued_dttm"] for item in child_instances)
            children_start_dates = (item["start_date"] for item in child_instances)
            children_end_dates = (item["end_date"] for item in child_instances)
            children_states = {item["state"] for item in child_instances}
            group_state = next((state for state in wwwutils.priority if state in children_states), None)
            group_queued_dttm = min(filter(None, children_queued_dttms), default=None)