void ConstrainHelixFitCurv(Int_t q=0,Double_t crv=-1,Double_t crverr=-1);
void RemoveHelixFitConstraint();
void SetVertexConstraint(const AliESDVertex* vtx);
void ConstrainHelixFitCurv(Int_t q=0,Double_t crv=-1,Double_t crverr=-1);
void RemoveHelixFitConstraint();
void SetVertexConstraint(const AliESDVertex* vtx);