// Overload function in GenotypeLikelihoodsCalculationModel so that, for an indel case, we
  // consider a deletion as part of the pileup,
  // so that per-sample DP will include deletions covering the event.
  protected int getFilteredDepth(ReadBackedPileup pileup) {
    int count = 0;
    for (PileupElement p : pileup) {
      if (p.isDeletion() || BaseUtils.isRegularBase(p.getBase())) count++;
    }

    return count;
  }
  private Map<String, AlignmentContext> getFilteredAndStratifiedContexts(
      UnifiedArgumentCollection UAC,
      ReferenceContext refContext,
      AlignmentContext rawContext,
      final GenotypeLikelihoodsCalculationModel.Model model) {

    if (!BaseUtils.isRegularBase(refContext.getBase())) return null;

    Map<String, AlignmentContext> stratifiedContexts = null;

    if (model.name().contains("INDEL")) {

      final ReadBackedPileup pileup =
          rawContext.getBasePileup().getMappingFilteredPileup(UAC.MIN_BASE_QUALTY_SCORE);
      // don't call when there is no coverage
      if (pileup.getNumberOfElements() == 0 && UAC.OutputMode != OUTPUT_MODE.EMIT_ALL_SITES)
        return null;

      // stratify the AlignmentContext and cut by sample
      stratifiedContexts = AlignmentContextUtils.splitContextBySampleName(pileup);

    } else if (model.name().contains("SNP")) {

      // stratify the AlignmentContext and cut by sample
      stratifiedContexts =
          AlignmentContextUtils.splitContextBySampleName(rawContext.getBasePileup());

      if (!(UAC.OutputMode == OUTPUT_MODE.EMIT_ALL_SITES
          && UAC.GenotypingMode
              != GenotypeLikelihoodsCalculationModel.GENOTYPING_MODE.GENOTYPE_GIVEN_ALLELES)) {
        int numDeletions = 0;
        for (final PileupElement p : rawContext.getBasePileup()) {
          if (p.isDeletion()) numDeletions++;
        }
        if (((double) numDeletions) / ((double) rawContext.getBasePileup().getNumberOfElements())
            > UAC.MAX_DELETION_FRACTION) {
          return null;
        }
      }
    }

    return stratifiedContexts;
  }