{"ast_node_type":"other","tokens":[{"end":58,"kind":"keyword","start":0,"text":"uncaptured_args.retain(|&(def_id,"}]}
                uncaptured_args.retain(|&(def_id, kind)| {
                // lifetime and are contravariant (i.e. covariant in argument position).
                    let Some(ty::Bivariant | ty::Contravariant) = self.variances.get(def_id) else {