}
    assertEquals(expectedSize, size2);
  }

  @CollectionSize.Require(ZERO)
  public void testIsEmptyYes() {
    assertTrue(multimap().isEmpty());
  }

  @CollectionSize.Require(absent = ZERO)
  public void testIsEmptyNo() {
    assertFalse(multimap().isEmpty());
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testSizeNullKey() {
    initMultimapWithNullKey();

    } catch (ClassCastException acceptable) {
      // allowed by the spec
    }
  }

  @MapFeature.Require(ALLOWS_NULL_KEY_QUERIES)
  public void testContainsEntryWithNullKeyAbsent() {
    assertFalse(getMap().entrySet().contains(Helpers.mapEntry(null, v0())));
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(ALLOWS_NULL_KEYS)
  public void testContainsEntryWithNullKeyPresent() {
    initMapWithNullKey();

    }
  }

  @CollectionSize.Require(ONE)
  public void testSingletonMapFirst() {
    assertEquals(a.getKey(), navigableMap.firstKey());
  }

  @CollectionSize.Require(ONE)
  public void testSingletonMapLast() {
    assertEquals(a.getKey(), navigableMap.lastKey());
  }

  @CollectionSize.Require(SEVERAL)
  public void testFirst() {
    assertEquals(a.getKey(), navigableMap.firstKey());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(SEVERAL)
  public void testMultimapRemoveDeletesFirstOccurrence() {
    resetContainer(mapEntry(k0(), v0()), mapEntry(k0(), v1()), mapEntry(k0(), v0()));

    List<V> list = multimap().get(k0());
    multimap().remove(k0(), v0());
    assertContentsInOrder(list, v1(), v0());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)

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

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemove_supportedPresent() {
    assertTrue(getMap().remove(k0(), v0()));
    expectMissing(e0());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemove_supportedPresentKeyWrongValue() {
    assertFalse(getMap().remove(k0(), v3()));

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

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemove_supportedPresent() {
    assertTrue(getMap().remove(k0(), v0()));
    expectMissing(e0());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemove_supportedPresentKeyWrongValue() {
    assertFalse(getMap().remove(k0(), v3()));

public class CollectionAddAllTester<E extends @Nullable Object>
    extends AbstractCollectionTester<E> {
  @CollectionFeature.Require(SUPPORTS_ADD)
  public void testAddAll_supportedNothing() {
    assertFalse("addAll(nothing) should return false", collection.addAll(emptyCollection()));
    expectUnchanged();
  }

  @CollectionFeature.Require(absent = SUPPORTS_ADD)
  public void testAddAll_unsupportedNothing() {
    try {
      assertFalse(

    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);
    }

public class QueuePollTester<E> extends AbstractQueueTester<E> {
  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testPoll_empty() {
    assertNull("emptyQueue.poll() should return null", getQueue().poll());
    expectUnchanged();
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ONE)
  public void testPoll_size1() {

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testRemove_empty() {
    try {
      getQueue().remove();
      fail("emptyQueue.remove() should throw");
    } catch (NoSuchElementException expected) {
    }
    expectUnchanged();
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ONE)
  public void testRemove_size1() {