};
  }

  public void test_contains_null_set_yes() {
    Iterable<@Nullable String> set = newHashSet("a", null, "b");
    assertTrue(Iterables.contains(set, null));
  }

  public void test_contains_null_set_no() {
    Iterable<String> set = newHashSet("a", "b");
    assertFalse(Iterables.contains(set, null));
  }

  public void test_contains_null_iterable_yes() {