{"ast_node_type":"function","tokens":[{"end":57,"kind":"keyword","start":0,"text":"pub(crate)"}]}
    pub(crate) fn top_subtree(&self) -> &tt::Subtree<S> {
impl<S: Copy> TopSubtree<S> {
        let tt::TokenTree::Subtree(subtree) = &self.0[0] else {