{"ast_node_type":"variable","tokens":[{"end":74,"kind":"keyword","start":0,"text":"let"}]}
        let source_root = db.file_source_root(file_id).source_root_id(db);
    let span_formatter = |file_id, text_range: TextRange| {
        let source_root = db.source_root(source_root).source_root(db);