@Override
  public int hashCode() {
    final int prime = 31;
    int result = 1;

    result = prime * (int) (xid ^ (xid >>> 32));
    result = prime * result + ((flags == null) ? 0 : flags.hashCode());
    result = prime * result + ((features == null) ? 0 : features.hashCode());
    return result;
  }