class YieldAndDiscountAddZeroSpreadCurve extends YieldAndDiscountCurve {

  @Override
  public double getInterestRate(final Double t) {
    double rate = _curves[0].getInterestRate(t);
    for (int loopcurve = 1; loopcurve < _curves.length; loopcurve++) {
      rate += _sign * _curves[loopcurve].getInterestRate(t);
    }
    return rate;
  }

  public  YieldAndDiscountAddZeroSpreadCurve(final String name, final boolean subtract, final YieldAndDiscountCurve... curves);

}