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());

  }

  @CollectionFeature.Require(absent = SUPPORTS_ADD)
  @CollectionSize.Require(absent = ZERO)
  public void testAddAll_unsupportedSomePresent() {
    assertThrows(
        UnsupportedOperationException.class,
        () -> collection.addAll(MinimalCollection.of(e3(), e0())));
    expectUnchanged();
  }

  @CollectionFeature.Require({SUPPORTS_ADD, FAILS_FAST_ON_CONCURRENT_MODIFICATION})

  @ListFeature.Require(SUPPORTS_SET)
  @CollectionSize.Require(absent = ZERO)
  public void testSet() {
    doTestSet(e3());
  }

  @CollectionSize.Require(absent = ZERO)
  @CollectionFeature.Require(ALLOWS_NULL_VALUES)
  @ListFeature.Require(SUPPORTS_SET)
  public void testSet_null() {
    doTestSet(null);
  }

  @CollectionSize.Require(absent = ZERO)

  }

  @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();

    int initialSize = getMap().size();
    assertEquals(

  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
  public void testIteratorRemoveMultiple() {
    Iterator<Entry<K, V>> entryItr = getMap().entrySet().iterator();
    while (entryItr.hasNext()) {
      entryItr.next();
      entryItr.remove();
    }
    assertTrue(getMap().isEmpty());
  }

  @CollectionSize.Require(absent = ZERO)

  }

  @CollectionSize.Require(SEVERAL)
  @CollectionFeature.Require(SUPPORTS_ITERATOR_REMOVE)
  public void testIteratorRemoveMultiple() {
    Iterator<Entry<K, V>> entryItr = getMap().entrySet().iterator();
    while (entryItr.hasNext()) {
      entryItr.next();
      entryItr.remove();
    }
    assertTrue(getMap().isEmpty());
  }

  @CollectionSize.Require(absent = ZERO)

public class MapPutIfAbsentTester<K, V> extends AbstractMapTester<K, V> {

  @MapFeature.Require(SUPPORTS_PUT)
  public void testPutIfAbsent_supportedAbsent() {
    assertNull(
        "putIfAbsent(notPresent, value) should return null", getMap().putIfAbsent(k3(), v3()));
    expectAdded(e3());
  }

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

public class MapRemoveEntryTester<K, V> extends AbstractMapTester<K, V> {
  @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()));

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

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

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

                (k, v) -> {
                  throw new AssertionFailedError();
                }));
    expectUnchanged();
  }

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(absent = ZERO)
  public void testComputeIfPresent_supportedPresent() {
    assertEquals(
        "computeIfPresent(present, function) should return new value",
        v3(),
        getMap()
            .computeIfPresent(
                k0(),