public sealed class eCommerce.Cart 

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace Dynamicweb.Examples.CSharp.Notifications.eCommerce
{
    /// <summary>
    /// Subscribing on Cart.Created event
    /// </summary>
    [Dynamicweb.Extensibility.Subscribe(Dynamicweb.Notifications.eCommerce.Cart.Created)]
    public class EcomCartCreatedObserver : Dynamicweb.Extensibility.NotificationSubscriber
    {
        /// <summary>
        /// This notification is thrown every time a cart is created. The notification appears when user adds first product to the cart.
        /// </summary>
        /// <param name="notification"></param>
        /// <param name="args"></param>
        public override void OnNotify(string notification, Dynamicweb.Extensibility.NotificationArgs args)
        {
            if (args == null || !(args is Dynamicweb.Notifications.eCommerce.Cart.CreatedArgs))
                return;
            Dynamicweb.Notifications.eCommerce.Cart.CreatedArgs cArgs = (Dynamicweb.Notifications.eCommerce.Cart.CreatedArgs)args;
            Dynamicweb.eCommerce.Shops.ShopCollection shops = Dynamicweb.eCommerce.Shops.Shop.getShops();
            if (shops == null || shops.Count == 0)
                return;
            cArgs.Order.ShopID = shops[0].ID;
            cArgs.Order.Save();
        }
    }
}