#include "Fit/Chi2FCN.h"

class MyFCN: public ROOT::Fit::Chi2Function{
  public:
    MyFCN(const ROOT::Fit::BinData&  data, const ROOT::Fit::Chi2Function::IModelFunction&  func): ROOT::Fit::Chi2Function(data,func) {}
    ~MyFCN(){}

    private:
    virtual double	DoEval(const double* x) const{
        double ret = ROOT::Fit::Chi2Function::DoEval(x);
        std::cout << "MyFCN::DoEval" << ret << endl;
        assert(0);
        return ret;
    }
};