@Override
  public int hashCode() {
    int keysHash = 0;
    int valuesHash = 0;
    for (int i = 0; i < myData.length; i += 2) {
      keysHash = keysHash ^ asKey(i).hashCode();
      valuesHash = valuesHash ^ asValue(i + 1).hashCode();
    }
    return keysHash + 31 * valuesHash;
  }
@Override
  public int hashCode()