check all occurences of CbmEvent::GetNofData in AnalysisTree interface
CbmEvent::GetNofData returns -1 in case of empty index. Need to check that it is accounted for in all occurences in AnalysisTree interface.
CbmEvent::GetNofData returns -1 in case of empty index. Need to check that it is accounted for in all occurences in AnalysisTree interface.