assertEquals(1 << 16, sixtyFiveThousandish.size());

    assertTrue(powerSet(makeSetOfZeroToTwentyNine()).contains(makeSetOfZeroToTwentyNine()));
    assertFalse(powerSet(makeSetOfZeroToTwentyNine()).contains(ImmutableSet.of(30)));
  }

  private static Set<Integer> makeSetOfZeroToTwentyNine() {
    return ContiguousSet.closedOpen(0, 30);
  }