expectMissing(Helpers.mapEntry(k0(), v0()));
    assertEquals(getNumElements() - 1, multimap().size());
    assertFalse(multimap().containsEntry(k0(), v0()));
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRetainAllPropagatesToMultimap() {
    multimap().entries().retainAll(Collections.singleton(Helpers.mapEntry(k0(), v0())));

  @CollectionSize.Require(SEVERAL)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testPropagatesRemoveToMultimap() {
    resetContainer(
        Helpers.mapEntry(k0(), v0()), Helpers.mapEntry(k0(), v3()), Helpers.mapEntry(k0(), v2()));
    Collection<V> result = multimap().asMap().get(k0());
    assertTrue(result.remove(v0()));
    assertFalse(multimap().containsEntry(k0(), v0()));

public class MultimapKeysTester<K, V> extends AbstractMultimapTester<K, V, Multimap<K, V>> {
  @CollectionSize.Require(SEVERAL)
  public void testKeys() {
    resetContainer(
        Helpers.mapEntry(k0(), v0()), Helpers.mapEntry(k0(), v1()), Helpers.mapEntry(k1(), v0()));
    Multiset<K> keys = multimap().keys();
    assertEquals(2, keys.count(k0()));
    assertEquals(1, keys.count(k1()));
    assertEquals(3, keys.size());

    assertEquals(multimap(), target);
  }

  @MapFeature.Require(SUPPORTS_PUT)
  public void testPutAll() {
    Multimap<K, V> source =
        getSubjectGenerator().create(Helpers.mapEntry(k0(), v3()), Helpers.mapEntry(k3(), v3()));
    assertTrue(multimap().putAll(source));
    assertTrue(multimap().containsEntry(k0(), v3()));
    assertTrue(multimap().containsEntry(k3(), v3()));
  }

public class MultimapKeysTester<K, V> extends AbstractMultimapTester<K, V, Multimap<K, V>> {
  @CollectionSize.Require(SEVERAL)
  public void testKeys() {
    resetContainer(
        Helpers.mapEntry(k0(), v0()), Helpers.mapEntry(k0(), v1()), Helpers.mapEntry(k1(), v0()));
    Multiset<K> keys = multimap().keys();
    assertEquals(2, keys.count(k0()));
    assertEquals(1, keys.count(k1()));
    assertEquals(3, keys.size());

            .create(
                Helpers.mapEntry(k0(), v0()),
                Helpers.mapEntry(k0(), v1()),
                Helpers.mapEntry(k0(), v0()));
    ListMultimap<K, V> multimap2 =
        getSubjectGenerator()
            .create(
                Helpers.mapEntry(k0(), v1()),
                Helpers.mapEntry(k0(), v0()),
                Helpers.mapEntry(k0(), v0()));

    } catch (UnsupportedOperationException e) {
      return;
    }

    map.put(null, unmappedValue);
    Entry<@Nullable K, V> entry = mapEntry(null, unmappedValue);
    assertTrue(entrySet.contains(entry));
    Entry<@Nullable K, @Nullable V> nonEntry = mapEntry(null, null);
    assertFalse(entrySet.contains(nonEntry));
  }

  public void testEntrySetContainsEntryNullKeyMissing() {
    Map<K, V> map;

  }

  @CollectionSize.Require(SEVERAL)
  @MapFeature.Require(SUPPORTS_PUT)
  public void testAsMapEntrySetReflectsPutSameKey() {
    resetContainer(Helpers.mapEntry(k0(), v0()), Helpers.mapEntry(k0(), v3()));

    Set<Entry<K, Collection<V>>> asMapEntrySet = multimap().asMap().entrySet();
    Collection<V> valueCollection = Iterables.getOnlyElement(asMapEntrySet).getValue();

    expectContents(Helpers.mapEntry(k1(), v0()));
    assertEquals(k1(), getMap().inverse().get(v0()));
    assertEquals(1, getMap().size());
    assertFalse(getMap().containsKey(k0()));
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(SEVERAL)
  public void testForcePutKeyAndValuePresent() {
    getMap().forcePut(k0(), v1());
    expectContents(Helpers.mapEntry(k0(), v1()), Helpers.mapEntry(k2(), v2()));

            mapEntry("one", 1),
            mapEntry("two", 2),
            mapEntry("three", 3));
  }

  public void testToImmutableBiMap_exceptionOnDuplicateKey() {
    Collector<Entry<String, Integer>, ?, ImmutableBiMap<String, Integer>> collector =
        ImmutableBiMap.toImmutableBiMap(Entry::getKey, Entry::getValue);
    try {
      Stream.of(mapEntry("one", 1), mapEntry("one", 11)).collect(collector);