/** Features supported by collections where only removal is allowed. */
  REMOVE_OPERATIONS(SUPPORTS_REMOVE, SUPPORTS_ITERATOR_REMOVE),

  SERIALIZABLE,
  SERIALIZABLE_INCLUDING_VIEWS(SERIALIZABLE),

  SUBSET_VIEW,
  DESCENDING_VIEW,

  /**
   * For documenting collections that support no optional features, such as {@link
   * java.util.Collections#emptySet}
   */
  NONE;

  @Override
  void putAll(Map<? extends K, ? extends V> map);

  // Views

  /**
   * {@inheritDoc}
   *
   * <p>Because a bimap has unique values, this method returns a {@link Set}, instead of the {@link
   * java.util.Collection} specified in the {@link Map} interface.
   */
  @Override
  Set<V> values();

  /**
   * Returns the inverse view of this bimap, which maps each of this bimap's values to its

 * invoke methods, they invoke methods on the {@code ForwardingSortedMultiset}.
 *
 * <p>The {@code standard} methods and any collection views they return are not guaranteed to be
 * thread-safe, even when all of the methods that they depend on are thread-safe.
 *
 * @author Louis Wasserman
 * @since 15.0
 */
@GwtCompatible(emulated = true)

                CollectionFeature.GENERAL_PURPOSE,
                CollectionFeature.SUPPORTS_ITERATOR_REMOVE,
                CollectionFeature.ALLOWS_NULL_QUERIES,
                MultisetFeature.ENTRIES_ARE_VIEWS)
            .named("EnumMultiset")
            .createTestSuite());
    suite.addTestSuite(EnumMultisetTest.class);
    return suite;
  }

  private static TestEnumMultisetGenerator enumMultisetGenerator() {

 * existing key-value pair has no effect.
 *
 * <p>Keys and values may be null. All optional multimap methods are supported, and all returned
 * views are modifiable.
 *
 * <p>This class is not threadsafe when any concurrent operations update the multimap. Concurrent
 * read operations will work correctly if the last write <i>happens-before</i> any reads. To allow

 * result, if the comparator is not consistent with equals, some of the standard implementations may
 * violate the {@code Set} contract.
 *
 * <p>The {@code standard} methods and the collection views they return are not guaranteed to be
 * thread-safe, even when all of the methods that they depend on are thread-safe.
 *
 * @author Mike Bostock
 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible

  @Override
  void putAll(Map<? extends K, ? extends V> map);

  // Views

  /**
   * {@inheritDoc}
   *
   * <p>Because a bimap has unique values, this method returns a {@link Set}, instead of the {@link
   * java.util.Collection} specified in the {@link Map} interface.
   */
  @Override
  Set<V> values();

  /**
   * Returns the inverse view of this bimap, which maps each of this bimap's values to its

    suite.addTest(
        MapTestSuiteBuilder.using(new ImmutableMapGenerator())
            .withFeatures(
                CollectionSize.ANY,
                CollectionFeature.SERIALIZABLE_INCLUDING_VIEWS,
                CollectionFeature.KNOWN_ORDER,
                MapFeature.REJECTS_DUPLICATES_AT_CREATION,
                CollectionFeature.ALLOWS_NULL_QUERIES)
            .named("ImmutableMap")

  /**
   * Returns a descending view of this multiset. Modifications made to either map will be reflected
   * in the other.
   */
  SortedMultiset<E> descendingMultiset();

  /**
   * Returns a view of this multiset restricted to the elements less than {@code upperBound},
   * optionally including {@code upperBound} itself. The returned multiset is a view of this

                CollectionFeature.ALLOWS_NULL_VALUES,
                CollectionFeature.SERIALIZABLE,
                CollectionFeature.GENERAL_PURPOSE,
                MultisetFeature.ENTRIES_ARE_VIEWS)
            .createTestSuite());
    suite.addTestSuite(LinkedHashMultisetTest.class);
    return suite;
  }

  private static TestStringMultisetGenerator linkedHashMultisetGenerator() {