'Load a CSV from tests/resources/calendars/{filename}.csv'

@staticmethod
def load_answer_key(filename):

    fullpath = join(dirname(abspath(__file__)), '../resources', 'calendars', (filename + '.csv'))
    return read_csv(fullpath, index_col=0, parse_dates=[0, 1, 2], date_parser=(lambda x: pd.Timestamp(x, tz='UTC')))
