public static /*@Real*/ double blackFormulaImpliedStdDevApproximation(
            final PlainVanillaPayoff payoff,
            @Real final double strike,
            @Real final double forward,
            @Real final double blackPrice) {
        // TODO : complete
        return blackFormulaImpliedStdDevApproximation(payoff, strike, forward, blackPrice, 1.0, 0.0);
    }
public static double blackFormulaImpliedStdDevApproximation(
            final PlainVanillaPayoff payoff,
            @Real final double strike,
            @Real final double forward,
            @Real final double blackPrice) {
       
        return blackFormulaImpliedStdDevApproximation(payoff, strike, forward, blackPrice, 1.0, 0.0);
    }
public static double blackformulaimpliedstddevapproximation( final plainvanillapayoff payoff, @real final double strike, @real final double forward, @real final double blackprice) { return blackformulaimpliedstddevapproximation(payoff, strike, forward, blackprice, 1.0, 0.0); }