// Yield Curves public abstract Handle <YieldTermStructure> YieldCurve(YieldCurveType type, string name, string configuration = DefaultConfiguration);
public override Handle <YieldTermStructure> YieldCurve(YieldCurveType type, string key, string configuration = "default") { throw new NotImplementedException(); //return _yieldCurves[new Tuple { key, type, configuration }, "yield curve"]; }