{"ast_node_type":"import","tokens":[{"end":60,"kind":"keyword","start":0,"text":"//"}]}
        // use `TextSize` as key to avoid repeated use stmts
        let mut refs: FxHashMap<FileId, Vec<(TextRange, String)>> = FxHashMap::default();
        let mut use_stmts_to_be_inserted = FxHashMap::default();