{"ast_node_type":"variable","tokens":[{"end":78,"kind":"keyword","start":0,"text":"let"}]}
        let illegal_sized_bound = self.predicates_require_illegal_sized_bound(
            .extend_to(self.tcx, pick.item.def_id, |def, _| self.tcx.mk_param_from_def(def));
            self.tcx.predicates_of(pick.item.def_id).instantiate(self.tcx, filler_args),