ArgumentChecker.notNull(blackMulticurves, "Black volatility for swaption and multicurve");
final GeneratorInstrument<GeneratorAttributeIR> generatorSwap = blackMulticurves.getBlackParameters().getGeneratorSwap();
Calendar calendar;
DayCount dayCountModification;
if (generatorSwap instanceof GeneratorSwapFixedIbor) {
final GeneratorSwapFixedIbor fixedIborGenerator = (GeneratorSwapFixedIbor) generatorSwap;
calendar = fixedIborGenerator.getCalendar();
dayCountModification = fixedIborGenerator.getFixedLegDayCount();
} else if (generatorSwap instanceof GeneratorSwapFixedON) {
final GeneratorSwapFixedON fixedONGenerator = (GeneratorSwapFixedON) generatorSwap;
calendar = fixedONGenerator.getOvernightCalendar();
dayCountModification = fixedONGenerator.getFixedLegDayCount();
} else if (generatorSwap instanceof GeneratorSwapFixedCompoundedONCompounded) {