void test_1_count_w_events (void)
{
  TStopwatch watcher;
  watcher.Start();

  TFile *f = new TFile ("caf_zcc.root", "READ");

  TTree *tree = (TTree*) f->Get("TMBTree");

  int entries = tree->Draw(">>partEventList", "MCpart.pdgid()==23");

  cout << "Number of events is " << partEventList->GetN() << endl; 
  cout << "Number of times Z appears: " << entries << endl;

  watcher.Stop();
  watcher.Print ("m");
  
}