def METHOD_NAME(is_date):
    cls = datetime.date if is_date else datetime.datetime
    values = [cls(2022, 1, 1), cls(2022, 1, 2)]
    fmts, _, _ = format_column(dt.date, values)
    strs = [str(f) for f in fmts]
    assert strs == ["2022-01-01", "2022-01-02"]