class AliHMPIDTracker: public AliTracker

 ctor. Create TObjArray of TClonesArray of AliHMPIDCluster

 destructor

 Interface callback methode invoked from AliReconstruction::WriteAlignmentData() to get position of MIP cluster in MARS associated to a current track.
 MIP cluster is reffered by index which is stored in AliESDtrack  ???????
 Arguments: idx- cluster index which is stored by HMPID in AliESDtrack
            point- reference to the object where to store the point
   Returns: status of operation  if FALSE then AliReconstruction::WriteAlignmentData() do not store this point to array of points for current track.

 Static method to find intersection in between given track and HMPID chambers
 Arguments: pTrk- ESD track; xPc,yPc- track intersection with PC in LORS [cm]
   Returns: intersected chamber ID or -1

 Static method to find intersection in between given track and HMPID chambers
 Arguments: pTrk- HMPID track; xPc,yPc- track intersection with PC in LORS [cm]
   Returns: intersected chamber ID or -1

 Interface callback methode invoked from AliReconstruction::RunTracking() to load HMPID clusters before PropagateBack() gets control. Done once per event.
 Arguments: pCluTree- pointer to clusters tree got by AliHMPIDLoader::LoadRecPoints("read") then AliHMPIDLoader::TreeR()
   Returns: error code (currently ignored in AliReconstruction::RunTraking())

 Interface pure virtual in AliTracker. Invoked from AliReconstruction::RunTracking() after invocation of AliTracker::LoadClusters() once per event
 Agruments: pEsd - pointer to ESD
   Returns: error code

 Static method to reconstruct the Cherenkov angle for all valid tracks of a given event.
 Arguments: pEsd- pointer ESD; pClu- pointer to clusters for all chambers; pNmean - pointer to all function Nmean=f(time)
 Returns: error code, 0 if no errors

 Algortihm: Loop over tracks

 1. Find the closest MIP cluster using fast tracks extrapolation method
 2. Propagate track to the MIP cluster using the STEER method
 3. Update the track information with MIP cluster (Improved angular and position resolution - to be used for Cherenkov angle calculation)
 4. Propagate back the constrained track to the radiator radius ( not exact yet)
 5. Propagation in the last 10 cm with the fast method
 6. Set ESDtrack information
 7. Calculate the Cherenkov angle

 Static method to reconstruct Theta Ckov for all valid tracks of a given event.
 Arguments: pEsd- pointer ESD; pClu- pointer to clusters for all chambers; pNmean - pointer to all function Nmean=f(time)
   Returns: error code, 0 if no errors

 Static method to reconstruct Theta Ckov for all valid tracks of a given event.
 Arguments: pEsd- pointer ESD; pClu- pointer to clusters for all chambers; pNmean - pointer to all function Nmean=f(time), pQthre - pointer to all function Qthre=f(time)
   Returns: error code, 0 if no errors

framework part