public ProductsModule(ProductStore productStore) : base("/products") { Get("", _ => { string productIdsString = this.Request.Query.productIds; var productIds = ParseProductIdsFromQueryString(productIdsString); var products = productStore.GetProductsByIds(productIds); return(this.Negotiate.WithModel(products).WithHeader("cache-control", "max-age:86400")); }); }