@SuppressWarnings("serial") // we're overriding default serialization
@ElementTypesAreNonnullByDefault
final class ImmutableEnumSet<E extends Enum<E>> extends ImmutableSet<E> {
  static <E extends Enum<E>> ImmutableSet<E> asImmutable(EnumSet<E> set) {
    switch (set.size()) {
      case 0:
        return ImmutableSet.of();
      case 1:
        return ImmutableSet.of(Iterables.getOnlyElement(set));
      default:

 * to avoid code-size bloat.
 *
 * @author Hayward Chan
 */
@ElementTypesAreNonnullByDefault
final class ImmutableEnumSet<E> extends ForwardingImmutableSet<E> {
  static <E> ImmutableSet<E> asImmutable(Set<E> delegate) {
    switch (delegate.size()) {
      case 0:
        return ImmutableSet.of();
      case 1:
        return ImmutableSet.of(Iterables.getOnlyElement(delegate));
      default:

@SuppressWarnings("serial") // we're overriding default serialization
@ElementTypesAreNonnullByDefault
final class ImmutableEnumSet<E extends Enum<E>> extends ImmutableSet<E> {
  static <E extends Enum<E>> ImmutableSet<E> asImmutable(EnumSet<E> set) {
    switch (set.size()) {
      case 0:
        return ImmutableSet.of();
      case 1:
        return ImmutableSet.of(Iterables.getOnlyElement(set));
      default: