}

  public void testAddAllPrimitiveIntStream() {
    StatsAccumulator accumulator = new StatsAccumulator();
    accumulator.addAll(megaPrimitiveDoubleStreamPart1().mapToInt(x -> (int) x));
    accumulator.addAll(megaPrimitiveDoubleStreamPart2().mapToInt(x -> (int) x));
    assertThat(accumulator.count()).isEqualTo(MEGA_STREAM_COUNT);
    assertThat(accumulator.mean()).isWithin(ALLOWED_ERROR * MEGA_STREAM_COUNT).of(MEGA_STREAM_MEAN);

  }

  public void testAddAllPrimitiveIntStream() {
    StatsAccumulator accumulator = new StatsAccumulator();
    accumulator.addAll(megaPrimitiveDoubleStreamPart1().mapToInt(x -> (int) x));
    accumulator.addAll(megaPrimitiveDoubleStreamPart2().mapToInt(x -> (int) x));
    assertThat(accumulator.count()).isEqualTo(MEGA_STREAM_COUNT);
    assertThat(accumulator.mean()).isWithin(ALLOWED_ERROR * MEGA_STREAM_COUNT).of(MEGA_STREAM_MEAN);

    assertThat(stats.min()).isEqualTo(MEGA_STREAM_MIN);
    assertThat(stats.max()).isEqualTo(MEGA_STREAM_MAX);
  }

  public void testOfPrimitiveIntStream() {
    Stats stats = Stats.of(megaPrimitiveDoubleStream().mapToInt(x -> (int) x));
    assertThat(stats.count()).isEqualTo(MEGA_STREAM_COUNT);
    assertThat(stats.mean()).isWithin(ALLOWED_ERROR * MEGA_STREAM_COUNT).of(MEGA_STREAM_MEAN);
    assertThat(stats.populationVariance())

        if (spaceChars == null) {
            if (spaceStr.startsWith("u")) {
                spaceChars = split(spaceStr, "u")
                        .get(stream -> stream.filter(StringUtil::isNotBlank).mapToInt(s -> Integer.parseInt(s, 16)).toArray());
            } else {
                // backward compatibility
                final int length = spaceStr.length();
                spaceChars = new int[length];