Executors.newSingleThreadScheduledExecutor(new ThreadFactoryImpl());
    // Add a listener to shut down the executor after the service is stopped. This ensures that the
    // JVM shutdown will not be prevented from exiting after this service has stopped or failed.
    // Technically this listener is added after start() was called so it is a little gross, but it

 *
 * <p>For interoperability between {@code ListenableFuture} and <b>{@code CompletableFuture}</b>,
 * consider <a href="https://github.com/lukas-krecan/future-converter">Future Converter</a>.
 *
 * @author Sven Mawson
 * @since 10.0 (replacing {@code Futures.makeListenable}, which existed in 1.0)
 */
@J2ktIncompatible
@GwtIncompatible
public final class JdkFutureAdapters {
  /**

      checkForConcurrentModification();
      checkState(current != null, "no calls to next() since the last call to remove()");
      if (current != next) { // after call to next()
        previous = current.previous;
        nextIndex--;
      } else { // after call to previous()
        next = current.next;
      }
      removeNode(current);
      current = null;
      expectedModCount = modCount;
    }

import java.util.concurrent.ExecutorService;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * Test case for {@link ListenableFutureTask}.
 *
 * @author Sven Mawson
 */
@NullUnmarked
public class ListenableFutureTaskTest extends TestCase {

  private ExecutorService exec;

  protected final CountDownLatch runLatch = new CountDownLatch(1);

import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CountDownLatch;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * @author Charles Fry
 */
@GwtCompatible
@J2ktIncompatible // MapMaker
@NullUnmarked
public class MapMakerTest extends TestCase {
  @GwtIncompatible // NullPointerTester
  public void testNullParameters() throws Exception {

import java.util.Set;
import java.util.concurrent.ExecutionException;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * {@link LoadingCache} tests that deal with empty caches.
 *
 * @author mike nonemacher
 */

@NullUnmarked
public class EmptyCachesTest extends TestCase {

  public void testEmpty() {
    for (LoadingCache<Object, Object> cache : caches()) {
      checkEmpty(cache);
    }
  }

import java.util.Set;
import java.util.concurrent.ExecutionException;
import junit.framework.TestCase;
import org.jspecify.annotations.NullUnmarked;

/**
 * {@link LoadingCache} tests that deal with empty caches.
 *
 * @author mike nonemacher
 */

@NullUnmarked
public class EmptyCachesTest extends TestCase {

  public void testEmpty() {
    for (LoadingCache<Object, Object> cache : caches()) {
      checkEmpty(cache);
    }
  }

import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import java.util.Arrays;

/**
 * {@link HashFunction} adapter for {@link MessageDigest} instances.
 *
 * @author Kevin Bourrillion
 * @author Dimitris Andreou
 */
@Immutable
final class MessageDigestHashFunction extends AbstractHashFunction implements Serializable {

  @SuppressWarnings("Immutable") // cloned before each use

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

/**
 * Tests for {@code AbstractBiMap}.
 *
 * @author Mike Bostock
 */
@NullUnmarked
public class AbstractBiMapTest extends TestCase {

  // The next two tests verify that map entries are not accessed after they're
  // removed, since IdentityHashMap throws an exception when that occurs.

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

/**
 * Tests for {@code AbstractBiMap}.
 *
 * @author Mike Bostock
 */
@NullUnmarked
public class AbstractBiMapTest extends TestCase {

  // The next two tests verify that map entries are not accessed after they're
  // removed, since IdentityHashMap throws an exception when that occurs.