class BloombergEQVanillaOptionChain {

  public BloombergEQVanillaOptionChain narrowByExpiry(int monthsFromToday) {
    return narrowByExpiry(LocalDate.now(OpenGammaClock.getInstance()), monthsFromToday);
  }

  public  BloombergEQVanillaOptionChain(Set<ExternalId> identifiers);
  public  BloombergEQVanillaOptionChain(List<ExternalId> identifiers);
  public  BloombergEQVanillaOptionChain(BloombergEQVanillaOptionChain original);

}