place the files in analysis/modules/ and compile as normal (scons).

In your steering file add the module as normal (For b2bii data set BelleFlag = True):

dualTrackTagger = register_module("DualTrackTagger")
dualTrackTagger.param("MCFlag",True)  # if this flag is selected additional truth histograms are output
dualTrackTagger.param("particleLists",["pi+:95eff"])   #input particle lists

Save decision and other info to output nTuple via CustomFloats extraInfo, example:

tools += ['CustomFloats[extraInfo(CurlTrack)]','^pi+'] #If track was marked curl (1 or 0)
tools += ['CustomFloats[extraInfo(ClusterSize)]','^pi+'] #How many tracks are considered possible curls/duplicates of each other

#only for MC
tools += ['CustomFloats[extraInfo(genParticleIndexMultiplicity)]','^pi+'] #Multiplicity of particles genParticleIndex, should correspond to number of reconstructed particles for single generated particle