message: Compatibility for parton type from stack for other generators thanPYTHIA
diff: @@ -877,8 +877,17 @@ void AliAnalysisTaskJetExtractorHF::CalculateInitialCollisionJets()
  if(MCEvent() && (MCEvent()->Stack()))
  {
  AliStack* stack = MCEvent()->Stack();
  - TParticle* parton1 = stack->Particle(6);
  - TParticle* parton2 = stack->Particle(7);
  + TParticle* parton1 = 0;
  + TParticle* parton2 = 0;
  + // PYTHIA: Get LO collision objects
  + if(stack->GetNtrack() >= 8)
  + {
  + parton1 = stack->Particle(6);
  + parton2 = stack->Particle(7);
  + }
  + else if(stack->GetNtrack() >= 7)
  + parton1 = stack->Particle(6);
  +
  if(parton1)
  {
  initialParton1_eta = parton1->Eta();
  