@Override
  @Nullable
  protected Map<Key, Value> getNullableIndexedData(int fileId) throws IOException, StorageException {
    if (myInMemoryMode.get()) {
      Map<Key, Value> map = myInMemoryKeysAndValues.get(fileId);
      if (map != null) return map;
    }
    return super.getNullableIndexedData(fileId);
  }
@Override
  @Nullable
  protected Map<Key, Value> getNullableIndexedData(int fileId)