/**
* Private constructor.
* @param spread The relative spread used in the call-spread pricing. The call spread strikes are (for an original strike K), K*(1-spread) and K*(1+spread).
*/
public PresentValueBlackVolatilityNodeSensitivityCallSpreadBlackForexCalculator(final double spread) {
_methodFxOptionDigital = new ForexOptionDigitalCallSpreadBlackMethod(spread);
}