// 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, Object> annotateSNP(AlignmentContext stratifiedContext, VariantContext vc) {

    if (!stratifiedContext.hasBasePileup()) return null;

    HashMap<Byte, Integer> alleleCounts = new HashMap<Byte, Integer>();
    for (Allele allele : vc.getAlternateAlleles()) alleleCounts.put(allele.getBases()[0], 0);

    ReadBackedPileup pileup = stratifiedContext.getBasePileup();
    int totalDepth = pileup.size();

    Map<String, Object> map = new HashMap<String, Object>();
    map.put(getKeyNames().get(0), totalDepth); // put total depth in right away

    if (totalDepth == 0) return map; // done, can not compute FA at 0 coverage!!

    int mq0 = 0; // number of "ref" reads that are acually mq0
    for (PileupElement p : pileup) {
      if (p.getMappingQual() == 0) {
        mq0++;
        continue;
      }
      if (alleleCounts.containsKey(p.getBase())) // non-mq0 read and it's an alt
      alleleCounts.put(p.getBase(), alleleCounts.get(p.getBase()) + 1);
    }

    if (mq0 == totalDepth) return map; // if all reads are mq0, there is nothing left to do

    // we need to add counts in the correct order
    String[] fracs = new String[alleleCounts.size()];
    for (int i = 0; i < vc.getAlternateAlleles().size(); i++) {
      fracs[i] =
          String.format(
              "%.3f",
              ((float) alleleCounts.get(vc.getAlternateAllele(i).getBases()[0]))
                  / (totalDepth - mq0));
    }

    map.put(getKeyNames().get(1), fracs);
    return map;
  }