#include "TFile.h"
#include "TTree.h"


void run() {
int nrunr=0;
int nsegm=0;
int nstream=2;
TFile*f = new TFile(Form("XYMG_run%d_%d_s%d.root",nrunr,nsegm,nstream),"recreate");
TTree*t= new TTree("t","XYMG DATA");
t->Refresh(); // I used Refresh(), but by replacing it by whatever action (i.e. t->Print() for example), it still works
exit(1);
}