assertTrue(actual.contains(list(1, 4)));
    assertTrue(actual.contains(list(2, 3)));
    assertTrue(actual.contains(list(2, 4)));
    assertFalse(actual.contains(list(3, 1)));
  }

  public void testCartesianProduct_equals() {
    Set<List<Integer>> cartesian = cartesianProduct(set(1, 2), set(3, 4));
    ImmutableSet<List<Integer>> equivalent =
        ImmutableSet.of(ImmutableList.of(1, 3), ImmutableList.of(1, 4), list(2, 3), list(2, 4));