erId ::
  forall f rs. (Functor f, UserId ∈ rs) =>
  (Int -> f Int) -> Record rs -> f (Record rs)
userId = rlens (Proxy :: Proxy UserId)


m
userId ::
  forall f rs. (Functor f, UserId ∈ rs) =>
  (Int -> f Int) -> Record rs -> f (Record rs)
userId = rlens (Proxy :: Proxy UserId)
userId = rlens (Proxy :: Proxy UserId)