@Override
public ApplicationTime initializeSub(final GenomeAnalysisEngine engine, final Walker walker) {
final BAQMode mode = WalkerManager.getWalkerAnnotation(walker, BAQMode.class);
this.refReader = engine.getReferenceDataSource().getReference();
this.cmode = engine.getArguments().BAQMode;
this.qmode = mode.QualityMode();
baqHMM = new BAQ(engine.getArguments().BAQGOP);
if ( qmode == BAQ.QualityMode.DONT_MODIFY )
throw new ReviewedGATKException("BUG: shouldn't create BAQ transformer with quality mode DONT_MODIFY");