* methods that they depend on are thread-safe.
 *
 * @author Mike Bostock
 * @author Louis Wasserman
 * @since 2.0
 */
@GwtCompatible
public abstract class ForwardingMapEntry<K extends @Nullable Object, V extends @Nullable Object>
    extends ForwardingObject implements Map.Entry<K, V> {
  // TODO(lowasser): identify places where thread safety is actually lost

  /** Constructor for use by subclasses. */

import java.io.ObjectOutputStream;
import java.io.Serializable;
import java.util.ConcurrentModificationException;
import java.util.Iterator;
import java.util.NoSuchElementException;
import org.jspecify.annotations.Nullable;

/**
 * Basic implementation of {@code Multiset<E>} backed by an instance of {@code
 * ObjectCountHashMap<E>}.
 *
 * <p>For serialization to work, the subclass must specify explicit {@code readObject} and {@code

import java.util.Set;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Creates map entries using sample keys and sample values.
 *
 * @author Jesse Wilson
 */
@GwtCompatible
@NullMarked
public abstract class TestMapEntrySetGenerator<
        K extends @Nullable Object, V extends @Nullable Object>
    implements TestSetGenerator<Map.Entry<K, V>> {
  private final SampleElements<K> keys;

import java.io.Serializable;
import java.util.Arrays;
import java.util.Comparator;
import org.jspecify.annotations.Nullable;

/** An ordering that tries several comparators in order. */
@GwtCompatible
final class CompoundOrdering<T extends @Nullable Object> extends Ordering<T>
    implements Serializable {
  final Comparator<? super T>[] comparators;

import com.google.common.annotations.GwtIncompatible;
import com.google.common.annotations.J2ktIncompatible;
import com.google.common.base.Preconditions;
import org.jspecify.annotations.Nullable;

/**
 * Implementation of {@link ImmutableSet} with exactly one element.
 *
 * @author Kevin Bourrillion
 * @author Nick Kralevich
 */
@GwtCompatible

import java.util.Set;
import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
import java.util.logging.Level;
import org.jspecify.annotations.Nullable;

/**
 * A helper which does some thread-safe operations for aggregate futures, which must be implemented
 * differently in GWT. Namely:
 *
 * <ul>
 *   <li>Lazily initializes a set of seen exceptions

// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
@NullMarked
public class MultimapSizeTester<K extends @Nullable Object, V extends @Nullable Object>
    extends AbstractMultimapTester<K, V, Multimap<K, V>> {

  public void testSize() {
    int expectedSize = getNumElements();
    Multimap<K, V> multimap = multimap();

 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#multimap">{@code Multimap}</a>.
 *
 * @author Jared Levy
 * @since 2.0
 */
@GwtCompatible
public interface ListMultimap<K extends @Nullable Object, V extends @Nullable Object>
    extends Multimap<K, V> {
  /**
   * {@inheritDoc}
   *
   * <p>Because the values for a given key may have duplicates and follow the insertion ordering,

 * "https://github.com/google/guava/wiki/NewCollectionTypesExplained#multimap">{@code Multimap}</a>.
 *
 * @author Jared Levy
 * @since 2.0
 */
@GwtCompatible
public interface ListMultimap<K extends @Nullable Object, V extends @Nullable Object>
    extends Multimap<K, V> {
  /**
   * {@inheritDoc}
   *
   * <p>Because the values for a given key may have duplicates and follow the insertion ordering,

  public int size() {
    return delegate.size();
  }

  @Override
  public boolean containsKey(@Nullable Object key) {
    return delegate.containsKey(key);
  }

  @Override
  public @Nullable V get(@Nullable Object key) {
    return delegate.get(key);
  }

  @Override
  public boolean equals(@Nullable Object object) {
    if (object == this) {
      return true;
    }