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

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

dualTrackTagger = register_module("DualTrackTagger")
dualTrackTagger.param("BelleFlag",True)
analysis_main.add_module(dualTrackTagger)

Save decision to output nTuple via CustomFloats extraInfo, example:

tools += ['CustomFloats[extraInfo(DualTrack)]','K_S0 -> ^pi+ ^pi-']