Reason why presentation definitions is an array in OID4VP?

[TimoGlastra]

The spec mentions that presentation_definition or presentation_definition_uri needs to be a PD object. This library also checks that not both the presentation_definition and presentation_definition_uri are present, so I think that means presentation definitions will never be an array?

I think it could help with simplifying the presentation parsing logic if we make presentation definition an object with one entry, especially as I'm now looking to add the new multi-vp for one PD logic.

Thoughts? Am I missing something?