assertFalse("addAll(nothing) should return false", collection.addAll(emptyCollection()));
    expectUnchanged();
  }

  @CollectionFeature.Require(absent = SUPPORTS_ADD)
  public void testAddAll_unsupportedNothing() {
    try {
      assertFalse(
          "addAll(nothing) should return false or throw", collection.addAll(emptyCollection()));
    } catch (UnsupportedOperationException tolerated) {
    }