@Dr15Jones @smuzaffar 
It's interesting that the duplicate checker (duplicateReflexLibrarySearch.py --dir ./ --dup) doesn't find this.
      std::pair<edm::Ptr<reco::CaloCluster>::key_type,edm::Ptr<reco::CaloCluster> >
and
      std::pair<unsigned long, edm::Ptr<reco::CaloCluster> >
are actually the same type:
      edm::Ptr<T>::key_type is actually "unsigned long"
https://cmssdt.cern.ch/SDT/lxr/source/DataFormats/Common/interface/Ptr.h#043
Chris, or Shahzad: is it our tools missing the duplicate, or are these two types somehow different in reflex?