select events/particles/pairs, mix… done by StHbtAnalysis objects
StHbtEventReader (Base class)
Now, StHbtManager iterates over all StHbtAnalysis in its
collection. They do what they want with the StHbtEvent
typedef list<StHbtBaseAnalysis*> StHbtAnalysisCollection;
typedef list<StHbtBaseAnalysis*>::iterator StHbtAnalysisIterator;