@Override
  public boolean equals(Object o) {
    if (this == o) {
      return true;
    }
    if (o == null || getClass() != o.getClass()) {
      return false;
    }

    CachedHolidaySource that = (CachedHolidaySource) o;

    if (!_underlying.equals(that._underlying)) {
      return false;
    }

    return true;
  }
 @Override
 public int hashCode() {
   return _underlying.hashCode();
 }