19   TFile fo(
"hits.root");
 
   21   std::vector<ExP01TrackerHit*>* 
hits;
 
   22   fo.GetListOfKeys()->Print();
 
   24   TIter next(fo.GetListOfKeys());
 
   27   while ((key=(TKey*)next()))
 
   29     fo.GetObject(key->GetName(), 
hits);
 
   32     cout << 
"Collection: " << key->GetName() << endl;
 
   33     cout << 
"Number of hits: " << hits->size() << endl;
 
   34     for (
int i=0;i!=hits->size();i++)