public Expiration loadConfiguration(ExpirationConfiguration config, String assigningAuthority) {
    Expiration result = null;

    if (config != null) {
      for (Expiration item : config.getExpirations()) {
        if (item.getAssigningAuthority().equalsIgnoreCase(assigningAuthority)) {
          result = item;
        }
      }

      if (result == null) {
        if (config.getDefaultDuration() >= 0 && config.getDefaultUnits().length() > 0) {
          result = new Expiration("", config.getDefaultUnits(), config.getDefaultDuration());
        }
      }
    }

    return result;
  }