{"ast_node_type":"variable","tokens":[{"end":68,"kind":"keyword","start":0,"text":"let"}]}
                let child_variances = self.tcx.variances_of(def_id);
            if def_id != self.root_def_id && self.tcx.is_descendant_of(def_id, self.root_def_id) {
                for (a, v) in args.iter().zip_eq(child_variances) {