{"ast_node_type":"variable","tokens":[{"end":53,"kind":"keyword","start":0,"text":"if"}]}
        if let ast::FnRetTy::Ty(output_ty) = ret_ty {
    fn visit_fn_ret_ty(&mut self, ret_ty: &'a ast::FnRetTy) {
            if let ast::TyKind::Never = output_ty.kind {