{"ast_node_type":"variable","tokens":[{"end":70,"kind":"keyword","start":0,"text":"if"}]}
                if let Ok(old_ty) = tcx.try_normalize_erasing_regions(
                let new_ty = ty::EarlyBinder::bind(ty).instantiate(tcx, new_args);
                    self.infcx.typing_env(self.infcx.param_env),