* equal to any other equality groups added to this tester.
   *
   * <p>The {@code @Nullable} annotations on the {@code equalityGroup} parameter imply that the
   * objects, and the array itself, can be null. That is for programmer convenience, when the
   * objects come from factory methods that are themselves {@code @Nullable}. In reality neither the
   * array nor its contents can be null, but it is not useful to force the use of {@code

// @Ignore affects the Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
@SuppressWarnings("JUnit4ClassUsedInJUnit3")
@NullMarked
public abstract class AbstractMapTester<K extends @Nullable Object, V extends @Nullable Object>
    extends AbstractContainerTester<Map<K, V>, Entry<K, V>> {
  protected Map<K, V> getMap() {
    return container;
  }

  @Override
  protected Collection<Entry<K, V>> actualContents() {

// @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();

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

/**
 * Creates sets, containing sample elements, to be tested.
 *
 * @author Kevin Bourrillion
 */
@GwtCompatible
@NullMarked
public interface TestListGenerator<E extends @Nullable Object> extends TestCollectionGenerator<E> {
  @Override
  List<E> create(Object... elements);

import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import org.jspecify.annotations.Nullable;

/** Emulation of Uninterruptibles in GWT. */
public final class Uninterruptibles {

  private Uninterruptibles() {}

  @CanIgnoreReturnValue
  public static <V extends @Nullable Object> V getUninterruptibly(Future<V> future)
      throws ExecutionException {
    try {
      return future.get();

import static java.util.Collections.singletonMap;

import org.jspecify.annotations.Nullable;

/**
 * GWT emulation of {@link SingletonImmutableBiMap}.
 *
 * @author Hayward Chan
 */
final class SingletonImmutableBiMap<K, V> extends ImmutableBiMap<K, V> {
  private final K singleKey;
  private final V singleValue;

  @Nullable transient SingletonImmutableBiMap<V, K> inverse;

  SingletonImmutableBiMap(K key, V value) {

import static junit.framework.Assert.fail;

import java.util.concurrent.ExecutionException;
import java.util.concurrent.Future;
import java.util.concurrent.TimeoutException;
import org.jspecify.annotations.Nullable;

/** Methods factored out so that they can be emulated differently in GWT. */
final class TestPlatform {
  static void verifyGetOnPendingFuture(Future<?> future) {
    try {
      future.get();
      fail();

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Collection;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;
import org.junit.Ignore;

/**
 * Base class for collection testers.
 *
 * @param <E> the element type of the collection to be tested.
 * @author Kevin Bourrillion
 */
@GwtCompatible

import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.logging.Handler;
import java.util.logging.LogRecord;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Tests may use this to intercept messages that are logged by the code under test. Example:
 *
 * <pre>
 *   TestLogHandler handler;
 *
 *   protected void setUp() throws Exception {

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;
import java.util.Collection;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;
import org.junit.Ignore;

/**
 * Base class for collection testers.
 *
 * @param <E> the element type of the collection to be tested.
 * @author Kevin Bourrillion
 */
@GwtCompatible