*
 * @author Hayward Chan
 */
@ElementTypesAreNonnullByDefault
@SuppressWarnings("serial") // Serialization only done in GWT.
public abstract class ForwardingImmutableSet<E> extends ImmutableSet<E> {
  private final transient Set<E> delegate;

  ForwardingImmutableSet(Set<E> delegate) {
    // TODO(cpovirk): are we over-wrapping?
    this.delegate = Collections.unmodifiableSet(delegate);
  }

  @Override

 * 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:

import java.util.Set;

/**
 * GWT emulation of {@link RegularImmutableSet}.
 *
 * @author Hayward Chan
 */
@ElementTypesAreNonnullByDefault
final class RegularImmutableSet<E> extends ForwardingImmutableSet<E> {
  static final RegularImmutableSet<Object> EMPTY =
      new RegularImmutableSet<Object>(Collections.emptySet());

  RegularImmutableSet(Set<E> delegate) {
    super(delegate);
  }

/**
 * GWT emulation of {@link com.google.common.collect.ImmutableSortedSet}.
 *
 * @author Hayward Chan
 */
@ElementTypesAreNonnullByDefault
public abstract class ImmutableSortedSet<E> extends ForwardingImmutableSet<E>
    implements SortedSet<E>, SortedIterable<E> {
  // TODO(cpovirk): split into ImmutableSortedSet/ForwardingImmutableSortedSet?

  // In the non-emulated source, this is in ImmutableSortedSetFauxverideShim,