private void Form1_Load(object sender, EventArgs e) { VirtualMarketOperations virtualMarketOperations = new VirtualMarketOperations(); virtualMarketOperations.AddToDefaultCategories(); Product product = new Product(); product.Brand = "Apple"; product.Model = "Macbook"; product.Price = 5000; product.Quantity = 100; product.ProductDescription = "gjdxklşkgnzpsdofkzösdf"; product.ProductType = "Laptop"; product.Category = "Computer"; virtualMarketOperations.AddProductToCategory(product); }