def test_retrieve_period_type_from_filename():
    assert (retrieve_period_type_from_filename('_hist.xml') == PeriodType.HISTORICAL)
    assert (retrieve_period_type_from_filename('no_period_type') is None)
def test_retrieve_period_type_from_filename():
    assert (retrieve_period_type_from_filename('_hist.xml') == PeriodType.HISTORICAL)
    assert (retrieve_period_type_from_filename('no_period_type') is None)