`UnmodifiableMultimap.forEach` uses the `Multimap.forEach` default implementation which involves listing entries, and creating a new lambda instead of simply passing the BiConsumer through to the protected instance. This is safe to pass directly though because `forEach(BiConsumer)` is a read-only operation.
}
    @Override
    public void clear() {
      throw new UnsupportedOperationException();
    }
    @Override
    public Map<K, Collection<V>> asMap() {
      Map<K, Collection<V>> result = map;
      if (result == null) {
        result =
            map =
                Collections.unmodifiableMap(
                    Maps.transformValues(
                        delegate.asMap(),
                        new Function<Collection<V>, Collection<V>>() {
                          @Override
                          public Collection<V> apply(Collection<V> collection) {
                            return unmodifiableValueCollection(collection);
                          }
                        }));
      }
      return result;
    }
    @Override
    public Collection<Entry<K, V>> entries() {
      Collection<Entry<K, V>> result = entries;
      if (result == null) {
        entries = result = unmodifiableEntries(delegate.entries());
      }
      return result;