IEnumerable data type: how to create a null object?

I have an object with several IEnumerable collections:

public class Product
{
    public int id {get;set;}
    public string name {get;set;}
    IEnumerable<CrossSell> CrossSell开发者_JAVA百科s {get;set;}
    IEnumerable<UpSell> UpSells {get;set;}
    IEnumerable<PricePromos> PricePromos {get;set;}
}

I need to create a null object (all properties are blank but not null). Apparently, I cannot just create an Enumerable item.

Other than creating an entirely new class, how could I do this?

Enumerable.Empty<T>() or just a new, zero-length array.

As cdhowie suggests, a zero-element array will work just as well. The syntax is new T[0].