{

     #include <buildtree.h>
 
     prova* myprova = new prova();

     TString filename = "events_tree.root";

     TFile * hfile = new TFile(filename,"RECREATE");

     TDirectoryFile *hpx    = new TDirectoryFile("event","");
     hfile->cd("event");

     tree = TTree("RecTracks","data");
     tree.Branch("myprovaBranch", "prova", &myprova, 16000, 0);
     
     tree.Fill();

     tree.Print();
     tree.Write();
     hfile->Close();
 }