added new class to add a reference to itself to a pat object as userdata
Merge branch 'master' into PUJetAssociation
fixed template syntax error
output collection
add ref
vector instead of view
Ref has value type
create ref by index
adds ref by index successfully
use either original jet (if available) or pointer to original for valuemap key
added messagelogger
testing refproducer with pu cleaner
properly adds a ref to reco::Candidate into a pat::Jet
default is to use original jets
re-enabled T_t