{"ast_node_type":"variable","tokens":[{"end":63,"kind":"keyword","start":0,"text":"let"}]}
            let input_type = callee_body.local_decls[input].ty;
        for (arg, input) in args.iter().zip(callee_body.args_iter()) {
            let arg_ty = arg.node.ty(&caller_body.local_decls, tcx);