что делает этот метод?

    def insert_items_in_db(self, item_list: List[ProductItem]):
        """Записываем в БД список товаров item_list [ProductItem], у которых должны быть заполнены поля:
        rrc_price
        title
        art_code
        url_code
        product_type_id
        product_guid
        so_guid_1c -  как product_guid, но c решеткой
        store_guid - гуид торговой точки, где будет запас товара (тут для каждой точки нужно остатки добавлять таким образом)
        quantity
        """
        self.delete_itemf_from_db(item_list)
        just_one = bool(len(item_list) == 1)
        values_to_products = ""
        values_to_sale_offer = ""
        values_to_wtb_stocks = ""
        values_to_wtb_stocks_sokolov = ""
        for prod in item_list:
            size = prod.size if prod.size else "0"
            values_to_products += str(
                tuple([prod.product_guid, prod.art_code, prod.url_code, prod.title, prod.product_type_id, prod.active, prod.rrc_price])
            )
            values_to_sale_offer += str(
                tuple(
                    [
                        f"(select id from b2c.products where guid_1c='{prod.product_guid}')",
                        prod.art_code,
                        prod.rrc_price,
                        prod.active,
                        True,
                        f"{prod.product_guid}#{size}",
                    ]
                )
            ).replace('"', "")
            values_to_wtb_stocks += str(
                tuple(
                    [
                        f"(select id from b2c.products where guid_1c='{prod.product_guid}')",
                        f"(select id from b2c.sale_offer where guid_1c='{prod.product_guid}#{size}')",
                        prod.store_guid,
                        prod.quantity,
                        prod.rrc_price,
                    ]
                )
            ).replace('"', "")
            values_to_wtb_stocks_sokolov += str(
                tuple(
                    [
                        f"(select id from b2c.products where guid_1c='{prod.product_guid}')",
                        f"(select id from b2c.sale_offer where guid_1c='{prod.product_guid}#{size}')",
                        prod.quantity,
                    ]
                )
            ).replace('"', "")
            end_of_value = ";" if just_one or item_list[-1] == prod else ","
            values_to_products += end_of_value
            values_to_sale_offer += end_of_value
            values_to_wtb_stocks += end_of_value
            values_to_wtb_stocks_sokolov += end_of_value

        with cursor_wrapper(self.connector) as cursor:
            cursor.execute(
                f"insert into b2c.products (guid_1c, article, url_code, name, product_type_id, active, min_rrc) values {values_to_products};"
            )
            cursor.execute(f"insert into b2c.sale_offer (product_id, article, rrc, active, in_range, guid_1c) values {values_to_sale_offer};")
            cursor.execute(f"insert into b2c.wtb_stocks (product_id, sale_offer_id, sale_point_id, quantity, price) values {values_to_wtb_stocks};")
            cursor.execute(f"insert into b2c.wtb_stocks_sokolov (product_id, sale_offer_id, quantity) values {values_to_wtb_stocks_sokolov};")