return Collections.unmodifiableList((List<E>) collection);
      } else {
        return Collections.unmodifiableCollection(collection);
      }
    }

    @Override
    Collection<V> wrapCollection(@ParametricNullness K key, Collection<V> collection) {
      if (collection instanceof List) {
        return wrapList(key, (List<V>) collection, null);
      } else if (collection instanceof NavigableSet) {