public async void StockUpdater(IStockSubscriber sub)
        {
            DateTime CurrentDateTimePlusFive = DateTime.Now.AddMinutes(5);

            while (CurrentDateTimePlusFive > DateTime.Now)
            {
                foreach (var Registrar in RegisteredRegistrars)
                {
                    Registrar.NotifySubscriber();
                }

                sub.StockAlertUpdate();
                System.Threading.Thread.Sleep(5000);
            }
        }