def METHOD_NAME(
    instrument_code, input_datapath=arg_not_supplied, input_prices=arg_not_supplied
):
    if input_datapath is None:
        print(
            "This will check the roll calendar in the default directory : are you are that's what you want to do?"
        )
    csv_roll_calendars = csvRollCalendarData(input_datapath)
    roll_calendar = csv_roll_calendars.get_roll_calendar(instrument_code)
    if input_prices is arg_not_supplied:
        prices = arcticFuturesContractPriceData()
    else:
        prices = input_prices
    dict_of_all_futures_contract_prices = prices.get_merged_prices_for_instrument(
        instrument_code
    )
    dict_of_futures_contract_prices = dict_of_all_futures_contract_prices.final_prices()
    print(roll_calendar)
    # checks - this might fail
    roll_calendar.check_if_date_index_monotonic()
    # this should never fail
    roll_calendar.check_dates_are_valid_for_prices(dict_of_futures_contract_prices)
    return roll_calendar