*/
class ImmutableCollections {

    private static final Map<?, ?> EMPTY_MAP = new AbstractImmutableMap<>() {
        @Override
        public Set<Entry<Object, Object>> entrySet() {
            return new AbstractImmutableSet<>() {
                @Override
                public Iterator<Entry<Object, Object>> iterator() {
                    return new Iterator<>() {
                        @Override