Ecommerce tracking: Properly tracking an emptied cart?

I didn’t see a mention of this in the docs, or anywhere on the forum. The problem or question I have is: How do I properly track a cart that has been emptied?

Do I just need to call trackEcommerceCartUpdate(0) without calling addEcommerceItem() first? Or do I need to do the second but change the product quantity to 0?

Thanks,

Edit: Solved, sort of. I just call the cartupdate with no items being added. The abandoned cart will show $0 revenue lost, no items but still an abandoned cart.