class UnorderedCurrencyPair implements ImmutableBean,
    UniqueIdentifiable, ObjectIdentifiable, Serializable {

  public static UnorderedCurrencyPair of(Currency ccy1, Currency ccy2) {
    return new UnorderedCurrencyPair(ccy1, ccy2);
  }

  @ImmutableConstructor private  UnorderedCurrencyPair(Currency currency1, Currency currency2);

}