optaplanner-benchmark/src/main/java/org/optaplanner/benchmark/impl/statistic/bestscore/BestScoreProblemStatistic.java
@Override
    public void writeGraphFiles(BenchmarkReport benchmarkReport) {
        List<XYPlot> plotList = new ArrayList<>(BenchmarkReport.CHARTED_SCORE_LEVEL_SIZE);
        int seriesIndex = 0;
        for (SingleBenchmarkResult singleBenchmarkResult : problemBenchmarkResult.getSingleBenchmarkResultList()) {
            List<XYSeries> seriesList = new ArrayList<>(BenchmarkReport.CHARTED_SCORE_LEVEL_SIZE);
            // No direct ascending lines between 2 points, but a stepping line instead
            XYItemRenderer renderer = new XYStepRenderer();
            if (singleBenchmarkResult.hasAllSuccess()) {
                BestScoreSubSingleStatistic subSingleStatistic = (BestScoreSubSingleStatistic)
                        singleBenchmarkResult.getSubSingleStatistic(problemStatisticType);
                List<BestScoreStatisticPoint> points = subSingleStatistic.getPointList();
                for (BestScoreStatisticPoint point : points) {
                    if (!point.getScore().isSolutionInitialized()) {
                        continue;
                    }
                    long timeMillisSpent = point.getTimeMillisSpent();
                    double[] levelValues = ScoreUtils.extractLevelDoubles(point.getScore());
                    for (int i = 0; i < levelValues.length && i < BenchmarkReport.CHARTED_SCORE_LEVEL_SIZE; i++) {
                        if (i >= seriesList.size()) {
                            seriesList.add(new XYSeries(
                                    singleBenchmarkResult.getSolverBenchmarkResult().getNameWithFavoriteSuffix()));
                        }
                        seriesList.get(i).add(timeMillisSpent, levelValues[i]);
                    }
                }
                // TODO if startingSolution is initialized and no improvement is made, a horizontal line should be shown
                // Draw a horizontal line from the last new best step to how long the solver actually ran
                long timeMillisSpent = singleBenchmarkResult.getTimeMillisSpent();
                double[] bestScoreLevels = ScoreUtils.extractLevelDoubles(singleBenchmarkResult.getMedian().getScore());
                for (int i = 0; i < bestScoreLevels.length && i < BenchmarkReport.CHARTED_SCORE_LEVEL_SIZE; i++) {
                    if (i >= seriesList.size()) {
                        seriesList.add(new XYSeries(
                                singleBenchmarkResult.getSolverBenchmarkResult().getNameWithFavoriteSuffix()));
                    }
                    seriesList.get(i).add(timeMillisSpent, bestScoreLevels[i]);
                }
                if (subSingleStatistic.getPointList().size() <= 1) {
                    // Workaround for https://sourceforge.net/tracker/?func=detail&aid=3387330&group_id=15494&atid=115494
                    renderer = new StandardXYItemRenderer(StandardXYItemRenderer.SHAPES_AND_LINES);
                }
            }
            if (singleBenchmarkResult.getSolverBenchmarkResult().isFavorite()) {
                // Make the favorite more obvious
                renderer.setSeriesStroke(0, new BasicStroke(2.0f));
            }
            for (int i = 0; i < seriesList.size(); i++) {
                if (i >= plotList.size()) {
                    plotList.add(createPlot(benchmarkReport, i));
                }
                plotList.get(i).setDataset(seriesIndex, new XYSeriesCollection(seriesList.get(i)));
                plotList.get(i).setRenderer(seriesIndex, renderer);
            }
            seriesIndex++;
        }
        graphFileList = new ArrayList<>(plotList.size());
        for (int scoreLevelIndex = 0; scoreLevelIndex < plotList.size(); scoreLevelIndex++) {
            String scoreLevelLabel = problemBenchmarkResult.findScoreLevelLabel(scoreLevelIndex);
            JFreeChart chart = new JFreeChart(
                    problemBenchmarkResult.getName() + " best " + scoreLevelLabel + " statistic",
                    JFreeChart.DEFAULT_TITLE_FONT, plotList.get(scoreLevelIndex), true);
            graphFileList.add(writeChartToImageFile(chart,
                    problemBenchmarkResult.getName() + "BestScoreStatisticLevel" + scoreLevelIndex));
        }
    }
@Override
    public void writeGraphFiles(BenchmarkReport benchmarkReport) {
        List<XYPlot> plotList = new ArrayList<>(BenchmarkReport.CHARTED_SCORE_LEVEL_SIZE);
        int seriesIndex = 0;
        for (SingleBenchmarkResult singleBenchmarkResult : problemBenchmarkResult.getSingleBenchmarkResultList()) {
            List<XYSeries> seriesList = new ArrayList<>(BenchmarkReport.CHARTED_SCORE_LEVEL_SIZE);
            // No direct ascending lines between 2 points, but a stepping line instead
            XYItemRenderer renderer = new XYStepRenderer();
            if (singleBenchmarkResult.hasAllSuccess()) {
                BestScoreSubSingleStatistic subSingleStatistic = (BestScoreSubSingleStatistic)
                        singleBenchmarkResult.getSubSingleStatistic(problemStatisticType);
                List<BestScoreStatisticPoint> points = subSingleStatistic.getPointList();
                for (BestScoreStatisticPoint point : points) {
                    if (!point.getScore().isSolutionInitialized()) {
                        continue;
                    }
                    long timeMillisSpent = point.getTimeMillisSpent();
                    double[] levelValues = ScoreUtils.extractLevelDoubles(point.getScore());
                    for (int i = 0; i < levelValues.length && i < BenchmarkReport.CHARTED_SCORE_LEVEL_SIZE; i++) {
                        if (i >= seriesList.size()) {
                            seriesList.add(new XYSeries(
                                    singleBenchmarkResult.getSolverBenchmarkResult().getNameWithFavoriteSuffix()));
                        }
                        seriesList.get(i).add(timeMillisSpent, levelValues[i]);
                    }
                }
                // TODO if startingSolution is initialized and no improvement is made, a horizontal line should be shown
                // Draw a horizontal line from the last new best step to how long the solver actually ran
                long timeMillisSpent = singleBenchmarkResult.getTimeMillisSpent();
                double[] bestScoreLevels = ScoreUtils.extractLevelDoubles(singleBenchmarkResult.getMedian().getScore());
                for (int i = 0; i < bestScoreLevels.length && i < BenchmarkReport.CHARTED_SCORE_LEVEL_SIZE; i++) {
                    if (i >= seriesList.size()) {
                        seriesList.add(new XYSeries(
                                singleBenchmarkResult.getSolverBenchmarkResult().getNameWithFavoriteSuffix()));
                    }
                    seriesList.get(i).add(timeMillisSpent, bestScoreLevels[i]);
                }
                if (subSingleStatistic.getPointList().size() <= 1) {
                    // Workaround for https://sourceforge.net/tracker/?func=detail&aid=3387330&group_id=15494&atid=115494
                    renderer = new StandardXYItemRenderer(StandardXYItemRenderer.SHAPES_AND_LINES);
                }
            }
            if (singleBenchmarkResult.getSolverBenchmarkResult().isFavorite()) {
                // Make the favorite more obvious
                renderer.setSeriesStroke(0, new BasicStroke(2.0f));
            }
            for (int i = 0; i < seriesList.size(); i++) {
                if (i >= plotList.size()) {
                    plotList.add(createPlot(benchmarkReport, i));
                }
                plotList.get(i).setDataset(seriesIndex, new XYSeriesCollection(seriesList.get(i)));
                plotList.get(i).setRenderer(seriesIndex, renderer);
            }
            seriesIndex++;
        }
        graphFileList = new ArrayList<>(plotList.size());
        for (int scoreLevelIndex = 0; scoreLevelIndex < plotList.size(); scoreLevelIndex++) {
            String scoreLevelLabel = problemBenchmarkResult.findScoreLevelLabel(scoreLevelIndex);
            JFreeChart chart = new JFreeChart(
                    problemBenchmarkResult.getName() + " best " + scoreLevelLabel + " statistic",
                    JFreeChart.DEFAULT_TITLE_FONT, plotList.get(scoreLevelIndex), true);
            graphFileList.add(writeChartToImageFile(chart,
                    problemBenchmarkResult.getName() + "BestScoreStatisticLevel" + scoreLevelIndex));
        }
    }
************************************************************************