{"ast_node_type":"other","tokens":[{"end":99,"kind":"keyword","start":0,"text":"args.insert(0,"}]}
                args.insert(0, (cx.tcx.types.self_param, _recv.span)); // dummy inserted for `self`
                let mut args = collect_args_tys_and_spans(args, true);
                (span, def_id, fn_gen_args, args)