hi! question, i am working on a 2 fa implementaiton. However, 2fa setting is optional (i.e i need to be able to update relationships to add or remove the caveat depending on some config). i tried to first delete/create relation but i cannot on same transaction send same relation twice. i am now just sending the relationship to TOUCH and it works to add the caveat of an existing relationship but i cannot figure out how to "clean" the caveat. setting *authzed.ContextualizedCaveat to nil doesnt work and trying to set *authzed.ContextualizedCaveat with some empty caveatName also fails, any suggestion? i need to be able to create/update several relationships in a transactional way , ty!