try {
      Sets.subSet(set, Range.closed(4, 8));
      fail("IllegalArgumentException expected");
    } catch (IllegalArgumentException expected) {
    }

    // These results are all incorrect, but there's no way (short of iterating over the result)
    // to verify that with an arbitrary ordering or comparator.
    assertEquals(ImmutableSortedSet.of(2, 4), Sets.subSet(set, Range.atLeast(4)));