assertThat(accumulator.count()).isEqualTo(MEGA_STREAM_COUNT);
    assertThat(accumulator.mean()).isWithin(ALLOWED_ERROR * MEGA_STREAM_COUNT).of(MEGA_STREAM_MEAN);
    assertThat(accumulator.populationVariance())
        .isWithin(ALLOWED_ERROR * MEGA_STREAM_COUNT)
        .of(MEGA_STREAM_POPULATION_VARIANCE);
    assertThat(accumulator.min()).isEqualTo(MEGA_STREAM_MIN);