docs: public static double getSwapAnnuity(double evaluationTime, Schedule schedule, DiscountCurve discountCurve, AnalyticModel model) {
  		double value = 0.0;
  		for(int periodIndex=0; periodIndex<schedule.getNumberOfPeriods(); periodIndex++) {
  			double paymentDate		= schedule.getPayment(periodIndex);
  			if(paymentDate <= evaluationTime) {
  				continue;
  			}
  
  			double periodLength		= schedule.getPeriodLength(periodIndex);
  			double discountFactor	= discountCurve.getDiscountFactor(model, paymentDate);
  			value += periodLength * discountFactor;
  		}
  		return value / discountCurve.getDiscountFactor(model, evaluationTime);
  	}