@Test public void powerSet() { MutableSet<String> set = MultiReaderUnifiedSet.newSetWith("1", "2", "3", "4").asReadUntouchable(); MutableSet<UnsortedSetIterable<String>> powerSet = set.powerSet(); Verify.assertSize((int) StrictMath.pow(2, set.size()), powerSet); Verify.assertContains(UnifiedSet.<String>newSet(), powerSet); Verify.assertContains(set, powerSet); }