}
  }

  protected boolean supportsRemove() {
    return true;
  }

  protected boolean supportsNullValues() {
    return false;
  }

  public void testClear() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    if (supportsRemove()) {
      table.clear();
      assertEquals(0, table.size());

    }
  }

  protected boolean supportsRemove() {
    return true;
  }

  protected boolean supportsNullValues() {
    return false;
  }

  public void testClear() {
    table = create("foo", 1, 'a', "bar", 1, 'b', "foo", 3, 'c');
    if (supportsRemove()) {
      table.clear();
      assertEquals(0, table.size());

  }

  // 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() {

public class MultimapRemoveEntryTester<K, V> extends AbstractMultimapTester<K, V, Multimap<K, V>> {
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemoveAbsent() {
    assertFalse(multimap().remove(k0(), v1()));
    expectUnchanged();
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemovePresent() {
    assertTrue(multimap().remove(k0(), v0()));

public class MultimapRemoveEntryTester<K, V> extends AbstractMultimapTester<K, V, Multimap<K, V>> {
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemoveAbsent() {
    assertFalse(multimap().remove(k0(), v1()));
    expectUnchanged();
  }

  @CollectionSize.Require(absent = ZERO)
  @MapFeature.Require(SUPPORTS_REMOVE)
  public void testRemovePresent() {
    assertTrue(multimap().remove(k0(), v0()));

  }

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

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

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

  private static final Feature<?>[] FOR_MAP_FEATURES_ONE = {
    CollectionSize.ONE,
    ALLOWS_NULL_VALUES,
    SUPPORTS_REMOVE,
    CollectionFeature.SUPPORTS_ITERATOR_REMOVE
  };

  private static final Feature<?>[] FOR_MAP_FEATURES_ANY = {
    CollectionSize.ANY,
    ALLOWS_NULL_VALUES,
    SUPPORTS_REMOVE,
    CollectionFeature.SUPPORTS_ITERATOR_REMOVE,

  private static final Feature<?>[] FOR_MAP_FEATURES_ONE = {
    CollectionSize.ONE,
    ALLOWS_NULL_VALUES,
    SUPPORTS_REMOVE,
    CollectionFeature.SUPPORTS_ITERATOR_REMOVE
  };

  private static final Feature<?>[] FOR_MAP_FEATURES_ANY = {
    CollectionSize.ANY,
    ALLOWS_NULL_VALUES,
    SUPPORTS_REMOVE,
    CollectionFeature.SUPPORTS_ITERATOR_REMOVE,

    if (!derivedFeatures.remove(CollectionFeature.SERIALIZABLE_INCLUDING_VIEWS)) {
      derivedFeatures.remove(CollectionFeature.SERIALIZABLE);
    }
    if (derivedFeatures.remove(MapFeature.SUPPORTS_REMOVE)) {
      derivedFeatures.add(CollectionFeature.SUPPORTS_REMOVE);
    }
    return derivedFeatures;
  }

  static Set<Feature<?>> computeEntriesFeatures(Set<Feature<?>> multimapFeatures) {

    if (mapFeatures.remove(CollectionFeature.SERIALIZABLE_INCLUDING_VIEWS)) {
      derivedFeatures.add(CollectionFeature.SERIALIZABLE);
    }
    if (mapFeatures.contains(MapFeature.SUPPORTS_REMOVE)) {
      derivedFeatures.add(CollectionFeature.SUPPORTS_REMOVE);
    }
    if (mapFeatures.contains(MapFeature.REJECTS_DUPLICATES_AT_CREATION)) {
      derivedFeatures.add(CollectionFeature.REJECTS_DUPLICATES_AT_CREATION);
    }