}
  }

  public static class ImmutableSetWithBadHashesGenerator extends TestCollidingSetGenerator
      // Work around a GWT compiler bug.  Not explicitly listing this will
      // cause the createArray() method missing in the generated javascript.
      // TODO: Remove this once the GWT bug is fixed.
      implements TestCollectionGenerator<Object> {
    @Override
    public Set<Object> create(Object... elements) {

import java.util.List;

/**
 * GWT emulated version of {@link SingletonImmutableList}.
 *
 * @author Hayward Chan
 */
@ElementTypesAreNonnullByDefault
final class SingletonImmutableList<E> extends ForwardingImmutableList<E> {

  final transient List<E> delegate;
  // This reference is used both by the custom field serializer, and by the
  // GWT compiler to infer the elements of the lists that needs to be

import com.google.common.annotations.J2ktIncompatible;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Hidden superclass of {@link FluentFuture} that provides us a place to declare special GWT
 * versions of the {@link FluentFuture#catching(Class, com.google.common.base.Function)
 * FluentFuture.catching} family of methods. Those versions have slightly different signatures.
 */
@GwtCompatible(emulated = true)

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.J2ktIncompatible;

/**
 * Hidden superclass of {@link Futures} that provides us a place to declare special GWT versions of
 * the {@link Futures#catching(ListenableFuture, Class, com.google.common.base.Function,
 * java.util.concurrent.Executor) Futures.catching} family of methods. Those versions have slightly
 * different signatures.
 */

import com.google.common.annotations.GwtCompatible;
import com.google.common.annotations.J2ktIncompatible;

/**
 * Hidden superclass of {@link Futures} that provides us a place to declare special GWT versions of
 * the {@link Futures#catching(ListenableFuture, Class, com.google.common.base.Function,
 * java.util.concurrent.Executor) Futures.catching} family of methods. Those versions have slightly
 * different signatures.
 */

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import java.util.Collection;
import java.util.Map;

/**
 * A dummy superclass to support GWT serialization of the element types of a {@link HashMultimap}.
 * The GWT supersource for this class contains a field for each type.
 *
 * <p>For details about this hack, see {@code GwtSerializationDependencies}, which takes the same

import com.google.common.annotations.J2ktIncompatible;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Hidden superclass of {@link FluentFuture} that provides us a place to declare special GWT
 * versions of the {@link FluentFuture#catching(Class, com.google.common.base.Function)
 * FluentFuture.catching} family of methods. Those versions have slightly different signatures.
 */
@GwtCompatible(emulated = true)

import java.util.Collection;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A GWT-only class only used by GWT emulations. It is used to consolidate the definitions of method
 * delegation to save code size.
 *
 * @author Hayward Chan
 */
// TODO: Make this class GWT serializable.
@ElementTypesAreNonnullByDefault
class ForwardingImmutableCollection<E> extends ImmutableCollection<E> {

package com.google.common.collect;

import com.google.common.annotations.GwtCompatible;
import java.util.Collection;
import java.util.Map;

/**
 * A dummy superclass to support GWT serialization of the element types of an {@link
 * ArrayListMultimap}. The GWT supersource for this class contains a field for each type.
 *
 * <p>For details about this hack, see {@code GwtSerializationDependencies}, which takes the same

 * versions of the {@link FluentFuture#catching(Class, com.google.common.base.Function)
 * FluentFuture.catching} family of methods. Those versions have slightly different signatures.
 */
@ElementTypesAreNonnullByDefault
abstract class GwtFluentFutureCatchingSpecialization<V extends @Nullable Object>
    extends AbstractFuture<V> {
  /*