@ApiStatus.Internal
  Map<String, Integer> dump() {
    assert myUnmodifiable;
    assert myNameStorage instanceof PersistentStringEnumerator;
    try {
      Collection<String> stubNames = ((PersistentStringEnumerator)myNameStorage).getAllDataObjects(null);
      Map<String, Integer> dump = new HashMap<>();
      for (String name : stubNames) {
        dump.put(name, myNameStorage.tryEnumerate(name));
      }
      return dump;
    }
    catch (IOException e) {
      LOG.error(e);
    }
    return Collections.emptyMap();
  }
@ApiStatus.Internal
  Map<String, Integer> dump()