So I'd deliberately left this one out because it's not the primary attribute of the Resource and I wasn't sure if it should be (i.e. we should filter on the content type primary key as opposed to language code)

i was testing on a multiligual so i've thinked at it like a missed option.... but yeah let's focus on porting filter on all the core component before

It's definitely missing and needs to be there before stable. but probably needs a proper discussion

ok i'll do a new pr

thankyou :)