assertEquals("Different ordered iteration", expected, iteratorElements);
  }

  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  @CollectionSize.Require(absent = ZERO)
  public void testIterator_nullElement() {
    initCollectionWithNullElement();
    List<E> iteratorElements = new ArrayList<>();
    for (E element : collection) { // uses iterator()
      iteratorElements.add(element);
    }

  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPutPresent() {
    int size = getNumElements();

    assertGet(k0(), v0());

    assertTrue(multimap().put(k0(), v3()));

    assertGet(k0(), v0(), v3());
    assertEquals(size + 1, multimap().size());
  }

  @MapFeature.Require(SUPPORTS_PUT)
  public void testPutTwoElements() {

    expectContents(expected);
  }

  @ListFeature.Require(SUPPORTS_ADD_WITH_INDEX)
  @CollectionSize.Require(absent = {ZERO, ONE})
  public void testSubList_subListAddAtIndexAffectsOriginalLargeList() {
    List<E> subList = getList().subList(2, 3);
    subList.add(0, e3());
    expectAdded(2, e3());
  }

  @ListFeature.Require(SUPPORTS_SET)
  @CollectionSize.Require(absent = {ZERO, ONE})

  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPutPresent() {
    int size = getNumElements();

    assertGet(k0(), v0());

    assertTrue(multimap().put(k0(), v3()));

    assertGet(k0(), v0(), v3());
    assertEquals(size + 1, multimap().size());
  }

  @MapFeature.Require(SUPPORTS_PUT)
  public void testPutTwoElements() {

    }
  }

  @CollectionSize.Require(ONE)
  public void testSingletonSetFirst() {
    assertEquals(a, sortedSet.first());
  }

  @CollectionSize.Require(ONE)
  public void testSingletonSetLast() {
    assertEquals(a, sortedSet.last());
  }

  @CollectionSize.Require(SEVERAL)
  public void testFirst() {
    assertEquals(a, sortedSet.first());
  }

  @CollectionSize.Require(SEVERAL)
  public void testLast() {

    return (ConcurrentMap<K, V>) super.getMap();
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testReplace_supportedPresent() {
    assertEquals(v0(), getMap().replace(k0(), v3()));
    expectReplacement(entry(k0(), v3()));
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testReplace_supportedPresentNoChange() {

    presentKeyNullValueEntry = entry(k0(), null);
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testPut_supportedPresent() {
    assertEquals("put(present, value) should return the old value", v0(), getMap().put(k0(), v3()));
    expectReplacement(entry(k0(), v3()));
  }

  @MapFeature.Require(SUPPORTS_PUT)
  public void testPut_supportedNotPresent() {

    new EqualsTester()
        .addEqualityGroup(multimap())
        .addEqualityGroup(getSubjectGenerator().create(targetEntries.toArray()))
        .testEquals();
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testEqualsMultimapWithNullKey() {
    Multimap<K, V> original = multimap();
    initMultimapWithNullKey();
    Multimap<K, V> withNull = multimap();
    new EqualsTester()

public class ListAddTester<E> extends AbstractListTester<E> {
  @CollectionFeature.Require(SUPPORTS_ADD)
  @CollectionSize.Require(absent = ZERO)
  public void testAdd_supportedPresent() {
    assertTrue("add(present) should return true", getList().add(e0()));
    expectAdded(e0());
  }

  @CollectionFeature.Require(absent = SUPPORTS_ADD)
  @CollectionSize.Require(absent = ZERO)
  /*
   * absent = ZERO isn't required, since unmodList.add() must

public class ListAddAtIndexTester<E> extends AbstractListTester<E> {
  @ListFeature.Require(SUPPORTS_ADD_WITH_INDEX)
  @CollectionSize.Require(absent = ZERO)
  public void testAddAtIndex_supportedPresent() {
    getList().add(0, e0());
    expectAdded(0, e0());
  }

  @ListFeature.Require(absent = SUPPORTS_ADD_WITH_INDEX)
  @CollectionSize.Require(absent = ZERO)
  /*
   * absent = ZERO isn't required, since unmodList.add() must