*
 * <p>The {@code standard} methods are not guaranteed to be thread-safe, even when all of the
 * methods that they depend on are thread-safe.
 *
 * @author Kevin Bourrillion
 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible
public abstract class ForwardingSet<E extends @Nullable Object> extends ForwardingCollection<E>
    implements Set<E> {

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.jspecify.annotations.NullMarked;

/**
 * Unit test for {@link HashMultiset}.
 *
 * @author Kevin Bourrillion
 * @author Jared Levy
 */
@GwtCompatible
@NullMarked
public class HashMultisetTest extends TestCase {

  @J2ktIncompatible
  @GwtIncompatible // suite
  @AndroidIncompatible // test-suite builders

import java.lang.ref.WeakReference;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Unit test for {@link Interners}.
 *
 * @author Kevin Bourrillion
 */
@NullUnmarked
public class InternersTest extends TestCase {

  public void testStrong_simplistic() {
    String canonical = "a";
    String not = new String("a");

import java.util.Spliterator;
import java.util.function.Consumer;
import org.jspecify.annotations.Nullable;

/**
 * {@code values()} implementation for {@link ImmutableMap}.
 *
 * @author Jesse Wilson
 * @author Kevin Bourrillion
 */
@GwtCompatible
final class ImmutableMapValues<K, V> extends ImmutableCollection<V> {
  private final ImmutableMap<K, V> map;

  ImmutableMapValues(ImmutableMap<K, V> map) {
    this.map = map;
  }

import java.util.Spliterator;
import java.util.Spliterators;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link ImmutableSet} with two or more elements.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class RegularImmutableSet<E> extends ImmutableSet.CachingAsList<E> {

import java.util.List;
import java.util.Map.Entry;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Unit test for {@link ImmutableClassToInstanceMap}.
 *
 * @author Kevin Bourrillion
 */
@NullUnmarked
final class ClassToInstanceMapTesting {
  abstract static class TestClassToInstanceMapGenerator
      implements TestMapGenerator<Class<?>, Impl> {

    @Override

import com.google.common.testing.NullPointerTester;
import java.util.Set;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Unit test for {@link Primitives}.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@NullUnmarked
public class PrimitivesTest extends TestCase {
  public void testIsWrapperType() {
    assertThat(Primitives.isWrapperType(Void.class)).isTrue();

import com.google.common.annotations.VisibleForTesting;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link ImmutableList} backed by a simple array.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@SuppressWarnings("serial") // uses writeReplace(), not default serialization
final class RegularImmutableList<E> extends ImmutableList<E> {

import com.google.common.annotations.GwtCompatible;
import com.google.common.primitives.Ints;
import org.jspecify.annotations.Nullable;

/**
 * Static methods for implementing hash-based collections.
 *
 * @author Kevin Bourrillion
 * @author Jesse Wilson
 * @author Austin Appleby
 */
@GwtCompatible
final class Hashing {
  private Hashing() {}

  /*

import junit.framework.Test;
import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.jspecify.annotations.NullUnmarked;

/**
 * Test suite covering {@link Doubles#asList(double[])}.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@NullUnmarked
@AndroidIncompatible // test-suite builders
public class DoubleArrayAsListTest extends TestCase {

  private static List<Double> asList(Double[] values) {