public static List <Product> CreditOff(int productId)
        {
            FileWriters writer = new FileWriters();

            ReadFromCsv.ProductList.Where(x => x.Id == productId).ToList().ForEach(x => x.CanBeBoughtOnCredit = false);
            writer.WriteToProductCsv("../../products.csv", ReadFromCsv.ProductList);
            return(null);
        }
        public static List <Product> Deactivate(int productId)
        {
            StregsystemCLI CLI    = new StregsystemCLI();
            FileWriters    writer = new FileWriters();

            ReadFromCsv.ProductList.Where(x => x.Id == productId).ToList().ForEach(x => x.Active = false);
            writer.WriteToProductCsv("../../products.csv", ReadFromCsv.ProductList);
            CLI.DisplayAktiveProducts();
            return(null);
        }