private void InsertReservedProducts(Product product)
 {
     DatabaseProductReservations.AddRange(product.ReservedProducts);
 }
 private void ClearPurchasedAndReservedProducts(Product product)
 {
     DatabaseProductPurchases.RemoveAll(p => p.Id == product.ID);
     DatabaseProductReservations.RemoveAll(p => p.Id == product.ID);
 }