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() {

  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testClear() {
    getMap().clear();
    assertTrue("After clear(), a map should be empty.", getMap().isEmpty());
    assertEquals(0, getMap().size());
    assertFalse(getMap().entrySet().iterator().hasNext());
  }

  @MapFeature.Require({FAILS_FAST_ON_CONCURRENT_MODIFICATION, SUPPORTS_REMOVE})
  @CollectionSize.Require(SEVERAL)

  }

  // retainAll(empty)

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testRetainAll_emptyPreviouslyEmpty() {
    expectReturnsFalse(empty);
    expectUnchanged();
  }

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testRetainAll_emptyPreviouslyEmptyUnsupported() {

    navigableMap = (NavigableMap<K, V>) getMap();
  }

  @CollectionSize.Require(ZERO)
  public void testEmptyMapFirst() {
    assertNull(navigableMap.firstEntry());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testEmptyMapPollFirst() {
    assertNull(navigableMap.pollFirstEntry());
  }

  @CollectionSize.Require(ZERO)
  public void testEmptyMapNearby() {

    }
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testEmptyMultisetPollLast() {
    assertNull(sortedMultiset.pollLastEntry());
  }

  @CollectionSize.Require(ONE)
  public void testSingletonMultisetFirst() {
    assertEquals(a, sortedMultiset.firstEntry());
  }

  @CollectionFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ONE)

    navigableMap = (NavigableMap<K, V>) getMap();
  }

  @CollectionSize.Require(ZERO)
  public void testEmptyMapFirst() {
    assertNull(navigableMap.firstEntry());
  }

  @MapFeature.Require(SUPPORTS_REMOVE)
  @CollectionSize.Require(ZERO)
  public void testEmptyMapPollFirst() {
    assertNull(navigableMap.pollFirstEntry());
  }

  @CollectionSize.Require(ZERO)
  public void testEmptyMapNearby() {

    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() {

    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)

    extends AbstractMultimapTester<K, V, Multimap<K, V>> {

  @MapFeature.Require({SUPPORTS_PUT, SUPPORTS_REMOVE, ALLOWS_NULL_VALUES})
  public void testReplaceValuesWithNullValue() {
    List<V> values = Arrays.asList(v0(), null, v3());
    multimap().replaceValues(k0(), values);
    assertGet(k0(), values);
  }

  @MapFeature.Require({SUPPORTS_PUT, SUPPORTS_REMOVE, ALLOWS_NULL_KEYS})
  public void testReplaceValuesWithNullKey() {

  @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