// part 1, hypothesis testing 
   SimpleLikelihoodRatioTestStat * testStat = new SimpleLikelihoodRatioTestStat(*bConfig->GetPdf(), *sbConfig->GetPdf());
   testStat->SetNullParameters(*bConfig->GetSnapshot());
   testStat->SetAltParameters(*sbConfig->GetSnapshot());

   HybridCalculator * hypoCalc = new HybridCalculator(*data, *sbConfig, *bConfig);
   hypoCalc->SetToys(10000, 10000);
   hypoCalc->ForcePriorNuisanceAlt(*sbConfig->GetPriorPdf());
   hypoCalc->ForcePriorNuisanceNull(*bConfig->GetPriorPdf());

   ToyMCSampler * sampler = (ToyMCSampler *)hypoCalc->GetTestStatSampler();
   sampler->SetNEventsPerToy(0); 
   sampler->SetTestStatistic(testStat); 

   HypoTestResult *  htr = hypoCalc->GetHypoTest();
   //htr->SetPValueIsRightTail(false);
   //htr->SetBackgroundAsAlt(true);
   htr->Print(); // how to get meaningfull CLs at this point?

   // part 2, inversion
   SimpleLikelihoodRatioTestStat * testStatFlip = new SimpleLikelihoodRatioTestStat(*sbConfig->GetPdf(), *bConfig->GetPdf());
   testStatFlip->SetNullParameters(*sbConfig->GetSnapshot());
   testStatFlip->SetAltParameters(*bConfig->GetSnapshot());

   HybridCalculator * hypoCalcFlip = new HybridCalculator(*data, *bConfig, *sbConfig);
   hypoCalcFlip->SetToys(10000, 10000);
   hypoCalcFlip->ForcePriorNuisanceAlt(*sbConfig->GetPriorPdf());
   hypoCalcFlip->ForcePriorNuisanceNull(*bConfig->GetPriorPdf());
   ToyMCSampler * samplerFlip = (ToyMCSampler *)hypoCalcFlip->GetTestStatSampler();
   samplerFlip->SetNEventsPerToy(0); 
   samplerFlip->SetTestStatistic(testStatFlip); 
   //htr = hypoCalcFlip->GetHypoTest();
   //htr->Print();

   HypoTestInverter * inverter = new HypoTestInverter(*hypoCalcFlip);
   inverter->SetConfidenceLevel(0.95);
   //inverter->UseCLs(false);
   inverter->SetFixedScan(5, 0.2, 0.8);
   HypoTestInverterResult * invResult = inverter->GetInterval();