* collection in setUp(), but that caused problems when a tester changed the
   * value of set or collection but not both.
   */
  protected final Set<E> getSet() {
    return (Set<E>) collection;
  }

  private List<E> values;
  private E a;
  private E b;
  private E c;

  @Override
  public void setUp() throws Exception {
    super.setUp();
    navigableSet = (NavigableSet<E>) getSet();
    values =
        Helpers.copyToList(
            getSubjectGenerator()
                .getSampleElements(getSubjectGenerator().getCollectionSize().getNumElements()));

   * collection in setUp(), but that caused problems when a tester changed the
   * value of set or collection but not both.
   */
  protected final Set<E> getSet() {
    return (Set<E>) collection;
  }

  private List<E> values;
  private @Nullable E a;
  private @Nullable E b;
  private @Nullable E c;

  @Override
  public void setUp() throws Exception {
    super.setUp();
    sortedSet = (SortedSet<E>) getSet();
    values =
        Helpers.copyToList(
            getSubjectGenerator()
                .getSampleElements(getSubjectGenerator().getCollectionSize().getNumElements()));

    assertTrue(
        "add(somePresent) should return true", getSet().addAll(MinimalCollection.of(e3(), e0())));
    expectAdded(e3());
  }

  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testAddAll_withDuplicates() {
    MinimalCollection<E> elementsToAdd = MinimalCollection.of(e3(), e4(), e3(), e4());
    assertTrue("add(hasDuplicates) should return true", getSet().addAll(elementsToAdd));
    expectAdded(e3(), e4());
  }

  @CollectionFeature.Require(SUPPORTS_ADD)
  @CollectionSize.Require(absent = ZERO)
  public void testAdd_supportedPresent() {
    assertFalse("add(present) should return false", getSet().add(e0()));
    expectUnchanged();
  }

  @CollectionFeature.Require(value = {SUPPORTS_ADD, ALLOWS_NULL_VALUES})
  @CollectionSize.Require(absent = ZERO)
  public void testAdd_supportedNullPresent() {