Service Api add parent relations to entryrelations when entry is variant

Steps to reproduce

Regarding maintance of relationship between products and variants, I want to be able to get all relations for an entry id regardless of whether it is a variant or a product. I use the service:
“/episerverapi/commerce/entries/{entry code}/entryrelations” however seems only to work if I use the product entry id – not if I use the variant entry id.