{"ast_node_type":"function","tokens":[{"end":75,"kind":"keyword","start":0,"text":"fn"}]}
    fn try_glue_to_last(vec: &mut Vec<TokenTree>, tt: &TokenTree) -> bool {
    // value indicates if gluing took place.
        if let Some(TokenTree::Token(last_tok, Spacing::Joint | Spacing::JointHidden)) = vec.last()