{"ast_node_type":"variable","tokens":[{"end":46,"kind":"keyword","start":0,"text":"let"}]}
    let iter = args.token_trees().split(|tt| {
    let mut token_trees = tt::TopSubtreeBuilder::new(args.top_subtree().delimiter);
        matches!(tt, tt::TtElement::Leaf(tt::Leaf::Punct(tt::Punct { char: ',', .. })))