{"ast_node_type":"variable","tokens":[{"end":71,"kind":"keyword","start":0,"text":"&&"}]}
            && let Some(arg) = receiver.map_or(args.get(*idx), |rcvr| {
        if let [(idx, _)] = args_referencing_param.as_slice()
                if *idx == 0 { Some(rcvr) } else { args.get(*idx - 1) }