Support for ProductGroup? #702
Description
Describe the feature
I might be missunderstanding something but the documentation comments for IsVariantOf on a Prouct talks about a ProductGroup (https://schema.org/ProductGroup) but I cannot seem to find that type.
My goal is to implement product variants as described here: https://developers.google.com/search/docs/appearance/structured-data/product-variants
Cheers!