}

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

  }

  public void testAddAllPrimitiveLongStream() {
    StatsAccumulator accumulator = new StatsAccumulator();
    accumulator.addAll(megaPrimitiveDoubleStreamPart1().mapToLong(x -> (long) x));
    accumulator.addAll(megaPrimitiveDoubleStreamPart2().mapToLong(x -> (long) 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 testOfPrimitiveLongStream() {
    Stats stats = Stats.of(megaPrimitiveDoubleStream().mapToLong(x -> (long) x));
    assertThat(stats.count()).isEqualTo(MEGA_STREAM_COUNT);
    assertThat(stats.mean()).isWithin(ALLOWED_ERROR * MEGA_STREAM_COUNT).of(MEGA_STREAM_MEAN);
    assertThat(stats.populationVariance())