assertPermutationsCount(40320, Collections2.permutations(newArrayList(1, 2, 3, 4, 5, 6, 7, 8)));
  }

  public void testPermutationSetSizeOverflow() {
    // 13 elements overflow an int
    assertEquals(
        Integer.MAX_VALUE,
        Collections2.permutations(newArrayList(1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)).size());