*/
  @IgnoreJRERequirement // Users will use this only if they're already using streams.
  public void addAll(DoubleStream values) {
    addAll(values.collect(StatsAccumulator::new, StatsAccumulator::add, StatsAccumulator::addAll));
  }

  /**
   * Adds the given values to the dataset. The stream will be completely consumed by this method.
   *
   * @param values a series of values

  private StatsAccumulator emptyAccumulator;
  private StatsAccumulator emptyAccumulatorByAddAllEmptyIterable;
  private StatsAccumulator emptyAccumulatorByAddAllEmptyStats;
  private StatsAccumulator oneValueAccumulator;
  private StatsAccumulator oneValueAccumulatorByAddAllEmptyStats;
  private StatsAccumulator twoValuesAccumulator;
  private StatsAccumulator twoValuesAccumulatorByAddAllStats;

  // These fields must satisfy the requirements of PairedStats' constructor as well as those of the
  // stat methods of this class.
  private final StatsAccumulator xStats = new StatsAccumulator();
  private final StatsAccumulator yStats = new StatsAccumulator();
  private double sumOfProductsOfDeltas = 0.0;

  /** Adds the given pair of values to the dataset. */
  public void add(double x, double y) {

    StatsAccumulator accumulator = new StatsAccumulator();
    accumulator.addAll(values);
    return accumulator.snapshot();
  }

  /**
   * Returns statistics over a dataset containing the given values.
   *
   * @param values a series of values
   */
  public static Stats of(double... values) {
    StatsAccumulator accumulator = new StatsAccumulator();

    StatsAccumulator accumulator = new StatsAccumulator();
    accumulator.addAll(MANY_VALUES);
    Stats stats = accumulator.snapshot();
    accumulator.add(999.999); // should do nothing to the snapshot
    return stats;
  }

  private static Stats buildLongManyValuesStatsSnapshot() {
    StatsAccumulator accumulator = new StatsAccumulator();
    accumulator.addAll(LONG_MANY_VALUES);