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

/**
 * Tests for ThreadFactoryBuilder.
 *
 * @author Kurt Alfred Kluever
 * @author Martin Buchholz
 */
@NullUnmarked
public class ThreadFactoryBuilderTest extends TestCase {
  private final Runnable monitoredRunnable =
      new Runnable() {
        @Override

import java.security.Key;
import java.security.NoSuchAlgorithmException;
import javax.crypto.Mac;

/**
 * {@link HashFunction} adapter for {@link Mac} instances.
 *
 * @author Kurt Alfred Kluever
 */
@Immutable
final class MacHashFunction extends AbstractHashFunction {

  @SuppressWarnings("Immutable") // cloned before each use
  private final Mac prototype;

import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * Tests for {@link Synchronized#queue} and {@link Queues#synchronizedQueue}.
 *
 * @author Kurt Alfred Kluever
 */
@NullUnmarked
public class SynchronizedQueueTest extends TestCase {

  protected Queue<String> create() {
    TestQueue<String> inner = new TestQueue<>();

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

/**
 * Tests for the MessageDigestHashFunction.
 *
 * @author Kurt Alfred Kluever
 */
@NullUnmarked
public class MessageDigestHashFunctionTest extends TestCase {
  private static final ImmutableSet<String> INPUTS = ImmutableSet.of("", "Z", "foobar");

 * default} methods. Instead, it inherits their default implementations. When those implementations
 * invoke methods, they invoke methods on the {@code ForwardingExecutorService}.
 *
 * @author Kurt Alfred Kluever
 * @since 10.0
 */
@J2ktIncompatible
@GwtIncompatible
public abstract class ForwardingExecutorService extends ForwardingObject
    implements ExecutorService {
  /** Constructor for use by subclasses. */

import org.jspecify.annotations.Nullable;
import sun.security.jca.ProviderList;
import sun.security.jca.Providers;

/**
 * Tests for the MacHashFunction.
 *
 * @author Kurt Alfred Kluever
 */
@NullUnmarked
public class MacHashFunctionTest extends TestCase {

  private static final ImmutableSet<String> INPUTS = ImmutableSet.of("", "Z", "foobar");

  private static final SecretKey MD5_KEY =

 * bounded queues, which either block or reject new elements when full.
 *
 * <p>This class is not thread-safe, and does not accept null elements.
 *
 * @author Kurt Alfred Kluever
 * @since 15.0
 */
@GwtCompatible
public final class EvictingQueue<E> extends ForwardingQueue<E> implements Serializable {

  private final Queue<E> delegate;

  @VisibleForTesting final int maxSize;

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

/**
 * Represents a {@linkplain System#getProperties() standard system property}.
 *
 * @author Kurt Alfred Kluever
 * @since 15.0
 */
@GwtIncompatible // java.lang.System#getProperty
public enum StandardSystemProperty {

  /** Java Runtime Environment version. */
  JAVA_VERSION("java.version"),

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

/**
 * Tests for ThreadFactoryBuilder.
 *
 * @author Kurt Alfred Kluever
 * @author Martin Buchholz
 */
@NullUnmarked
public class ThreadFactoryBuilderTest extends TestCase {
  private final Runnable monitoredRunnable =
      new Runnable() {
        @Override

import java.util.Set;
import junit.framework.TestCase;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * Unit test for {@link Optional}.
 *
 * @author Kurt Alfred Kluever
 */
@NullMarked
@GwtCompatible
public final class OptionalTest extends TestCase {
  @SuppressWarnings("NullOptional")
  public void testToJavaUtil_static() {
    assertThat(Optional.toJavaUtil(null)).isNull();