return Collections.unmodifiableCollection(collection);
  }

  @Override
  public void clear() {
    // Clear each collection, to make previously returned collections empty.
    for (Collection<V> collection : map.values()) {
      collection.clear();
    }
    map.clear();
    totalSize = 0;
  }

  // Views

  /**
   * {@inheritDoc}
   *

   * Returns an array containing all of the elements in the specified collection; the runtime type
   * of the returned array is that of the specified array. If the collection fits in the specified
   * array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the
   * specified array and the size of the specified collection.
   *
   * <p>If the collection fits in the specified array with room to spare (i.e., the array has more

        parent.add(index, element);
    }

    @Override
    public boolean addAll(final Collection<? extends Map<String, Object>> c) {
        return parent.addAll(c);
    }

    @Override
    public boolean addAll(final int index, final Collection<? extends Map<String, Object>> c) {
        return parent.addAll(index, c);
    }

    @Override
    public void clear() {

        "containsAll(sameElements) should return true",
        collection.containsAll(MinimalCollection.of(createSamplesArray())));
  }

  @SuppressWarnings("ModifyingCollectionWithItself")
  public void testContainsAll_self() {
    assertTrue("containsAll(this) should return true", collection.containsAll(collection));
  }

  public void testContainsAll_partialOverlap() {
    assertFalse(

 *
 * <ul>
 *   <li><b>Shallow immutability.</b> Elements can never be added, removed or replaced in this
 *       collection. This is a stronger guarantee than that of {@link
 *       Collections#unmodifiableCollection}, whose contents change whenever the wrapped collection
 *       is modified.
 *   <li><b>Null-hostility.</b> This collection will never contain a null element.

    return emptySet();
  }

  private Collection<Method> suppressForEmptySortedMap() {
    return emptySet();
  }

  protected Collection<Method> suppressForSingletonMap() {
    return emptySet();
  }

  protected Collection<Method> suppressForHashMap() {
    return emptySet();
  }

  protected Collection<Method> suppressForHashtable() {

      return standardRemove(object);
    }

    @Override
    public boolean removeAll(Collection<?> collection) {
      return standardRemoveAll(collection);
    }

    @Override
    public boolean retainAll(Collection<?> collection) {
      return standardRetainAll(collection);
    }

    @Override
    public Object[] toArray() {
      return standardToArray();
    }

  @Override
  Collection<V> wrapCollection(@ParametricNullness K key, Collection<V> collection) {
    return new WrappedSet(key, (Set<V>) collection);
  }

  // Following Javadoc copied from SetMultimap.

  /**
   * {@inheritDoc}
   *
   * <p>Because a {@code SetMultimap} has unique values for a given key, this method returns a
   * {@link Set}, instead of the {@link Collection} specified in the {@link Multimap} interface.
   */
  @Override

    public Builder<E> addAll(Iterable<? extends E> elements) {
      if (elements instanceof Collection) {
        Collection<?> collection = (Collection<?>) elements;
        ensureRoomFor(collection.size());
        if (collection instanceof ImmutableCollection) {
          ImmutableCollection<?> immutableCollection = (ImmutableCollection<?>) collection;
          size = immutableCollection.copyIntoArray(contents, size);
          return this;

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

  @CollectionFeature.Require(absent = SUPPORTS_REMOVE)
  @CollectionSize.Require(absent = ZERO)