{"ast_node_type":"variable","tokens":[{"end":98,"kind":"keyword","start":0,"text":"let"}]}
        let storage = inner.region_constraint_storage.as_ref().expect("regions already resolved");
        assert!(!UndoLogs::<UndoLog<'_>>::in_snapshot(&inner.undo_log));
        assert!(storage.data.is_empty(), "{:#?}", storage.data);