{"ast_node_type":"variable","tokens":[{"end":71,"kind":"keyword","start":0,"text":"let"}]}
        let attr = token.parent_ancestors().find_map(ast::Attr::cast)?;
        let token = sema.parse_or_expand(file_id).covering_element(tokens[0]).into_token()?;
        let expansions = sema.expand_derive_macro(&attr)?;