virtual void AddSimDigit(Int_t branch, AliITSdigit *d);
virtual void AddSimDigit(Int_t branch,Float_t phys,Int_t* digits,
Int_t* tracks,Int_t *hits,Float_t* trkcharges);
virtual void AddSimDigit(Int_t branch, AliITSdigit *d);
virtual void AddSimDigit(Int_t branch,Float_t phys,Int_t* digits,
Int_t* tracks,Int_t *hits,Float_t* trkcharges);