DiscountItems union
Entitled or prerequisite items on a discount. An item could be either collection or product or product_variant.
Possible types
[AllDiscountItems](https://shopify.dev/docs/admin-api/graphql/reference/discounts-and-marketing/alldiscountitems)
[DiscountCollections](https://shopify.dev/docs/admin-api/graphql/reference/discounts-and-marketing/discountcollections)
[DiscountProducts](https://shopify.dev/docs/admin-api/graphql/reference/discounts-and-marketing/discountproducts)