* varargs array, not the array itself
     */
    expectAdded((E) null);
  }

  @CollectionFeature.Require(value = SUPPORTS_ADD, absent = ALLOWS_NULL_VALUES)
  public void testAddAll_nullUnsupported() {
    List<E> containsNull = singletonList(null);
    assertThrows(NullPointerException.class, () -> collection.addAll(containsNull));
    expectUnchanged();
    expectNullMissingWhenNullUnsupported(