{"ast_node_type":"function","tokens":[{"end":35,"kind":"keyword","start":0,"text":"fn"}]}
        fn upvar_is_local_variable(
    fn walk_captures(&self, closure_expr: &hir::Closure<'_>) -> Result<(), Cx::Error> {
            upvars: Option<&FxIndexMap<HirId, hir::Upvar>>,