public Map getUsedIndexes() {
    Map map = (Map) indexInfo.get();
    if (map == null) {
      return Collections.EMPTY_MAP;
    }
    return map;
  }
This should be called only when one query execution on one gemfire node is done. NOT for each
buckets.
geode-core/src/main/java/org/apache/geode/cache/query/internal/IndexTrackingQueryObserver.java