using namespace RooStats;

void test2(){
  int nsb = 30;   // number of observed events
  int nb = 28; // number of background events
  
  RooWorkspace w("w",true);
  
  // make Poisson model
  w.factory("sum:nexp(s[2,0,20],b[0,0,50])");
  // Poisson of (nsb_obs | s+b)
  w.factory("Poisson:psb(nsb_obs[50,0,70],nexp)");
  // Poisson of (nb_obs | b)
  w.factory("Poisson:pb(nb_obs[50,0,50],b)");
  //The model
  w.factory("PROD:model(psb,pb)");
  
  
  w.var("nb_obs")->setVal(nb);
  w.var("nb_obs")->setConstant(true); // needed for being treated as global observables
 
  //set value of observed events
  RooRealVar *nsb_obs = w.var("nsb_obs");
  nsb_obs->setVal(nsb);

 

  // make data set with the namber of observed events
  RooDataSet data("data","",*nsb_obs);
  data.add(*nsb_obs);
  w.import(data);

  w.Print();


   ModelConfig mc("Smodel",&w);
   mc.SetPdf(*w.pdf("model"));
   mc.SetParametersOfInterest(*w.var("s"));
   mc.SetObservables(*w.var("nsb_obs"));
  
   // these are needed for the hypothesis tests
   mc.SetSnapshot(*w.var("s"));
   mc.SetGlobalObservables(*w.var("nb_obs"));


   //construct the B hypo (s=0)
   RooStats::ModelConfig* bModel = (RooStats::ModelConfig*) mc.Clone("Bmodel") ;
   RooRealVar* poi = (RooRealVar*) bModel->GetParametersOfInterest()->first();
   poi->setVal(0);
   bModel->SetSnapshot(*poi);
   
   mc.Print();
   cout<<"---------"<<endl;
   bModel->Print();
   // import model in the workspace 
   w.import(mc);
   w.import(*bModel);

   TString fileName = "test2.out1.root"; 

   
   // write workspace in the file (recreate file if already existing)
   w.writeToFile(fileName, true);

   
}