{"ast_node_type":"variable","tokens":[{"end":34,"kind":"keyword","start":0,"text":"let"}]}
                    let new_args =
                for t in [Ty::new_mut_ref, Ty::new_imm_ref, |_, _, t| t] {
                        tcx.mk_args_from_iter(targs.iter().map(|arg| match arg.as_type() {