def next_execution(args):
    """
    Returns the next execution datetime of a DAG at the command line.
    >>> airflow next_execution tutorial
    2018-08-31 10:38:00
    """
    dag = get_dag(args)

    if dag.is_paused:
        print("[INFO] Please be reminded this DAG is PAUSED now.")

    if dag.latest_execution_date:
        next_execution_dttm = dag.following_schedule(dag.latest_execution_date)

        if next_execution_dttm is None:
            print("[WARN] No following schedule can be found. " +
                  "This DAG may have schedule interval '@once' or `None`.")

        print(next_execution_dttm)
    else:
        print("[WARN] Only applicable when there is execution record found for the DAG.")
        print(None)
Returns the next execution datetime of a DAG at the command line.
    >>> airflow next_execution tutorial
    2018-08-31 10:38:00