assertThrows(IllegalArgumentException.class, Stats::meanOf);
    assertThrows(IllegalArgumentException.class, () -> Stats.meanOf(ImmutableList.<Number>of()));
    assertThat(Stats.meanOf(ONE_VALUE)).isWithin(ALLOWED_ERROR).of(ONE_VALUE);
    assertThat(Stats.meanOf(POSITIVE_INFINITY)).isPositiveInfinity();
    assertThat(Stats.meanOf(NEGATIVE_INFINITY)).isNegativeInfinity();
    assertThat(Stats.meanOf(NaN)).isNaN();