},
        Spliterator.SIZED,
        size());
  }

  @Override
  public void forEach(BiConsumer<? super K, ? super V> action) {
    checkNotNull(action);
    map.forEach(
        (key, valueCollection) -> valueCollection.forEach(value -> action.accept(key, value)));
  }

  @Override
  Map<K, Collection<V>> createAsMap() {
    return new AsMap(map);
  }