Mocking events with AAA

public virtual void AddProducts(string name, IWarehouse warehouse)
{
    try {
        warehouse.SomethingWentWrong += Alarm;
        
        var products = warehouse.GetProducts(name);
        products.ForEach(p => _products.Add(p));
    }
    finally {
        warehouse.SomethingWentWrong -= Alarm;
    }
}
...
public void Alarm(object sender, WarehouseEventArgs args)
{
    if (args.BadRequest)
        IsRed = true;
}

[Test, Isolated]
public void SomethingWentWrong_IsRed()
{
    var warehouse = MockManager.MockObject<IWarehouse>();
    var alarm = warehouse.ExpectAddEvent("SomethingWentWrong");
    warehouse.ExpectRemoveEvent("SomethingWentWrong");
    warehouse.ExpectAndReturn("GetProducts", FireAndReturn(alarm, DefaultProducts));

    var cart = new ShoppingCart();
    cart.AddProducts("foo", warehouse.MockedInstance);

    Assert.IsTrue(cart.IsRed, "Cart should go to the 'red' state if there was a bad request to the wharehouse.");
}
...
private static DynamicReturnValue FireAndReturn(MockedEvent alarm, List<Product> result)
{
    return (args, obj) => {
        alarm.Fire(null, new WarehouseEventArgs { BadRequest = true });
        return result;
    };
}