{"ast_node_type":"variable","tokens":[{"end":92,"kind":"keyword","start":0,"text":"let"}]}
                        let msg = format!("you need `{trait_type}` instead of `{rcvr_ty}`");
                            Ty::new_ref(self.tcx, *region, *t_type, mutability.invert());
                        let mut kind = &self_expr.kind;