@Override
  public boolean exists(String path, int options) {
    if (path.equals("/")) {
      return true;
    }
    return pathToRecords.containsKey(path);
  }
{@inheritDoc}

This is not thread safe if some thread is setting {@link #readLatch}.
ambry-clustermap/src/test/java/com/github/ambry/clustermap/MockHelixPropertyStore.java