def METHOD_NAME(cls, parser):
    p_operation = parser.add_subparsers(dest="operation", metavar="OPERATION", required=True)
    p_measure = p_operation.add_parser(
        "measure", help="read measured values")
    p_log = p_operation.add_parser(
        "log", help="log measured values")
    p_log.add_argument(
        "-i", "--interval", metavar="TIME", type=float, required=True,
        help="sample each TIME seconds")
    DataLogger.add_subparsers(p_log)