code: public static double[] determineStandardDeviationDoubles(
              List<? extends BenchmarkResult> benchmarkResultList, Score averageScore, int successCount) {
          if (successCount <= 0) {
              return null;
          }
          if (averageScore == null) {
              throw new IllegalArgumentException("Average score (" + averageScore + ") cannot be null.");
          }
          // averageScore can no longer be null
          double[] differenceSquaredTotalDoubles = null;
          for (BenchmarkResult benchmarkResult : benchmarkResultList) {
              if (benchmarkResult.hasAllSuccess()) {
                  Score difference = benchmarkResult.getAverageScore().subtract(averageScore);
                  // Calculations done on doubles to avoid common overflow when executing with an int score > 500 000
                  double[] differenceDoubles = ScoreUtils.extractLevelDoubles(difference);
                  if (differenceSquaredTotalDoubles == null) {
                      differenceSquaredTotalDoubles = new double[differenceDoubles.length];
                  }
                  for (int i = 0; i < differenceDoubles.length; i++) {
                      differenceSquaredTotalDoubles[i] += Math.pow(differenceDoubles[i], 2.0);
                  }
              }
          }
          double[] standardDeviationDoubles = new double[differenceSquaredTotalDoubles.length];
          for (int i = 0; i < differenceSquaredTotalDoubles.length; i++) {
              standardDeviationDoubles[i] = Math.pow(differenceSquaredTotalDoubles[i] / successCount, 0.5);
          }
          return standardDeviationDoubles;
      }
docs: Calculates standard deviation of {@link BenchmarkResult#getAverageScore()}s from {@code averageScore}.
  @param averageScore not null
  @return standard deviation double values