docs: public static final double chooseMostCommonRightHandClassAccuracy(SummaryConfusionMatrix m) {
      final double total = m.sumOfallCells();
      double max = 0.0;
      for (final Symbol right : m.rightLabels()) {
        max = Math.max(max, m.columnSum(right));
      }
      return DoubleUtils.XOverYOrZero(max, total);
    }