if (phasedCurGenotypeRelativeToPrevious) {
Genotype prevHetGenotype = phaseWindow.phaseRelativeToGenotype();
SNPallelePair prevAllelePair = new SNPallelePair(prevHetGenotype);
if (!prevHetGenotype.hasAnyAttribute(HP_KEY))
throw new ReviewedGATKException("Internal error: missing haplotype markings for previous genotype, even though we put it there...");
String[] prevPairNames = (String[]) prevHetGenotype.getAnyAttribute(HP_KEY);
String[] curPairNames = ensurePhasing(allelePair, prevAllelePair, prevPairNames, pr.haplotype);
Genotype phasedGt = new GenotypeBuilder(gt)
.alleles(allelePair.getAllelesAsList())