def METHOD_NAME(
    self,
    period_start: datetime.datetime,
    period_end: datetime.datetime = arg_not_supplied,
) -> list:
    if period_end is arg_not_supplied:
        period_end = datetime.datetime.now()
    find_dict = dict(fill_datetime={"$gte": period_start, "$lt": period_end})
    list_of_order_dicts = self.mongo_data.get_list_of_result_dict_for_custom_dict(
        find_dict
    )
    order_ids = [order_dict["order_id"] for order_dict in list_of_order_dicts]
    return order_ids