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

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