message: ATO-465 - adding MC multiplicity information
  ```
diff: #include "TVectorD.h"
  #include "TStatToolkit.h"
  #include "AliESDtools.h"
  +#include "TVectorF.h"
  using namespace std;
  ClassImp(AliAnalysisTaskFilteredTree)
  @@ -1559,15 +1560,20 @@ void AliAnalysisTaskFilteredTree::ProcessAll(AliESDEvent *const esdEvent, AliMCE
  "indexNearestComb="<<indexNearestComb; // index of nearest track for constrained track
  if (mcEvent){
  + Int_t multMCTracksAll= mcEvent->GetNumberOfTracks();
  static AliTrackReference refDummy;
  if (!refITS) refITS = &refDummy;
  if (!refTRD) refTRD = &refDummy;
  if (!refTOF) refTOF = &refDummy;
  if (!refEMCAL) refEMCAL = &refDummy;
  if (!refPHOS) refPHOS = &refDummy;
  + TVectorF vtxMCS(3,vtxMC.GetArray());
  downscaleCounter++;
  (*fTreeSRedirector)<<"highPt"<<
  "multMCTrueTracks="<<multMCTrueTracks<< // mC track multiplicities
  + "multMCTracksAll="<< multMCTracksAll<< // mcEvent->GetNumberOfTracks();
  + "mcStackSize="<<mcStackSize<< // MC stack sides - tack->GetNtrack();
  + "vtxMC.="<< &vtxMCS<<
  "nrefITS="<<nrefITS<< // number of track references in the ITS
  "nrefTPC="<<nrefTPC<< // number of track references in the TPC
  "nrefTRD="<<nrefTRD<< // number of track references in the TRD
  