filter(createUnfiltered(contents), EVEN).headSet(i));
        }
      }
    }

    @SuppressWarnings("unchecked")
    public void testTailSet() {
      for (List<Integer> contents : SAMPLE_INPUTS) {
        for (int i = 0; i < 10; i++) {
          assertEquals(
              filter((C) createUnfiltered(contents).tailSet(i), EVEN),