QLNet.SimpleQuote.setValue C# (CSharp) Метод

        public double setValue(double? value)
        {
            double? diff = value - value_;
            if (diff != 0)
            {
                value_ = value;
                notifyObservers();
            }
            return diff.GetValueOrDefault();
        }

 public override double value(double x)
 {
     if (x.IsNotEqual(vol_.value()))
     {
         vol_.setValue(x);
         engine_.calculate();
     }
     return(results_.value.Value - targetValue_);
 }