text: #pragma once
  
  #include "G4THitsMap.hh"
  #include "G4UserEventAction.hh"
  #include <vector>
  
  class EventActionHistogram : public G4UserEventAction {
    public:
      EventActionHistogram();
      void EndOfEventAction(const G4Event* event) override;
  
    private:
      bool fIDsCached;
      std::vector<G4int> fHitCollectionIDs;
  };
  