{"ast_node_type":"variable","tokens":[{"end":98,"kind":"keyword","start":0,"text":"let"}]}
        let old_ast_id_map = mem::replace(&mut self.ast_id_map, self.db.ast_id_map(self.file_id));
        let old_file_id = mem::replace(&mut self.file_id, macro_call_id.into());
        let old_span_map = mem::replace(&mut self.span_map, SpanMap::ExpansionSpanMap(span_map));