//
@Override
protected double zeroYieldImpl(final double t) {
//org.comment: to be fixed: user-defined daycounter should be used
final InterestRate zeroRate = originalCurve.currentLink().
zeroRate(t, comp, freq, true);
final InterestRate spreadedRate =
new InterestRate(zeroRate.rate() + spread.currentLink().value(),
zeroRate.dayCounter(),
zeroRate.compounding(),
zeroRate.frequency());
return spreadedRate.equivalentRate(t, Compounding.Continuous, Frequency.NoFrequency).rate();
}