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

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

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

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testReplaceEntry_supportedPresent() {
    try {
      assertTrue(getMap().replace(k0(), v0(), v3()));
      expectReplacement(entry(k0(), v3()));
    } catch (ClassCastException tolerated) { // for ClassToInstanceMap
      expectUnchanged();
    }
  }

  @MapFeature.Require(SUPPORTS_PUT)

public class BiMapRemoveTester<K, V> extends AbstractBiMapTester<K, V> {
  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemoveKeyRemovesFromInverse() {
    getMap().remove(k0());
    expectMissing(e0());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testRemoveKeyFromKeySetRemovesFromInverse() {

    assertEquals(2, multimap().size());
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testPropagatesRemoveLastElementToMultimap() {
    Collection<V> result = multimap().asMap().get(k0());
    assertTrue(result.remove(v0()));
    assertGet(k0());
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testPropagatesClearToMultimap() {

    assertNull(navigableSet.higher(e0()));
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testEmptySetPollLast() {
    assertNull(navigableSet.pollLast());
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ONE)
  public void testSingletonSetPollFirst() {
    assertEquals(a, navigableSet.pollFirst());

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

    expectAdded(e0());
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(ZERO)
  public void testPutPresentKeyDifferentValue() {
    getMap().put(k0(), v0());
    getMap().put(k0(), v1());
    // verify that the bimap is changed, and that the old inverse mapping
    // from v1 -> v0 is deleted
    expectContents(Helpers.mapEntry(k0(), v1()));
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(ZERO)

  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)
  public void testClearPropagatesToGet() {
    for (K key : sampleKeys()) {
      resetContainer();
      Collection<V> collection = multimap().get(key);
      multimap().clear();
      assertEmpty(collection);
    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)

    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() {

      // success
    }
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemove_notPresent() {
    assertNull("remove(notPresent) should return null", getMap().remove(k3()));
    expectUnchanged();
  }

  @MapFeature.Require({SUPPORTS_REMOVE, ALLOWS_NULL_KEYS})
  @CollectionSize.Require(absent = ZERO)
  public void testRemove_nullPresent() {
    initMapWithNullKey();