void unload() {
      loaded = false;
      desc = null;
      for (final StatDescriptor stat : stats) {
        stat.unload();
      }
      descriptorMap.clear();
      descriptorMap = null;
    }
Frees up any resources no longer needed after the archive file is closed. Returns true if
this resource is no longer needed.
geode-core/src/main/java/org/apache/geode/internal/statistics/StatArchiveReader.java