@Override
    public String toString() {
      return "HashMapSegmentLayout[segmentNo=" + segmentIndex + ", segmentSize=" + segmentSize + "]" +
             "[hashSuffix: " + hashSuffix() + ", depth: " + hashSuffixDepth() + "]" +
             "{" + aliveEntriesCount() + " alive entries of " + entriesCount() + "}";
    }
@Override
    public String toString()