public static void Main(string[] args)
        {
            var context = new ProductsSystemDbContext();

            // Execute the following method if do not have the
            // database in sql server
            // It will add sample data automatically
            // Firstly ensure that in the App.config file
            // you have the name of your sql server in the
            // connection string
            //Configuration.InitializeDatabase(context);
            Thread.CurrentThread.CurrentCulture = new CultureInfo("en-US");
            var data = ProductsSystemData.GetInstance(context);
            //var userInterface = new ConsoleUserInterface();
            //var engine = Engine.GetInstance(userInterface, data);
            //engine.Run();


            var product = data.Products.All().Select(
                p => new { ProductName = p.Name, VendorName = p.Vendor.Name, QuantitySold = p.Sales.Sum(s => s.Quantity * p.Price) });
            var json = JsonExporter.JsonExporter.ToJson(product);

            Console.WriteLine(json);
        }
 public GenericRepository(ProductsSystemDbContext context)
 {
     _context    = context;
     this._dbSet = _context.Set <T>();
 }