import java.util.concurrent.TimeUnit;

/**
 * Factory methods for {@link ExecutorService} for testing.
 *
 * @author Chris Nokleberg
 * @since 14.0
 */
@GwtIncompatible
public final class TestingExecutors {
  private TestingExecutors() {}

  /**
   * Returns a {@link ScheduledExecutorService} that never executes anything.
   *
   * <p>The {@code shutdownNow} method of the returned executor always returns an empty list despite

   * rather than just the {@link RuntimeException} or {@link Error} that should be possible. (And in
   * fact the static type of {@link Throwable} is occasionally justified even for a method with no
   * {@code throws} clause: Some such methods can in fact throw a checked exception (e.g., by
   * calling code written in Kotlin).) Typically, we want to let a {@link Throwable} from such a

   * rather than just the {@link RuntimeException} or {@link Error} that should be possible. (And in
   * fact the static type of {@link Throwable} is occasionally justified even for a method with no
   * {@code throws} clause: Some such methods can in fact throw a checked exception (e.g., by
   * calling code written in Kotlin).) Typically, we want to let a {@link Throwable} from such a

  protected AbstractExecutionThreadService() {}

  /**
   * Start the service. This method is invoked on the execution thread.
   *
   * <p>By default this method does nothing.
   */
  protected void startUp() throws Exception {}

  /**
   * Run the service. This method is invoked on the execution thread. Implementations must respond

 * <h3>Extension</h3>
 *
 * If you want a class like {@code FluentFuture} but with extra methods, we recommend declaring your
 * own subclass of {@link ListenableFuture}, complete with a method like {@link #from} to adapt an
 * existing {@code ListenableFuture}, implemented atop a {@link ForwardingListenableFuture} that
 * forwards to that future and adds the desired methods.
 */
@GwtCompatible

   *
   * <p><b>Java 11+ users:</b> use {@link Writer#nullWriter()} instead. Note that the {@link
   * CharStreams} method returns a singleton writer whose {@code close} method has no effect, while
   * the {@link Writer#nullWriter()} method returns a new instance whose methods throw after the
   * instance is {@link Writer#close() closed}.
   *
   * @since 15.0
   */
  public static Writer nullWriter() {

    private static final ImmutableMap<String, Method> typeVariableMethods;

    static {
      ImmutableMap.Builder<String, Method> builder = ImmutableMap.builder();
      for (Method method : TypeVariableImpl.class.getMethods()) {
        if (method.getDeclaringClass().equals(TypeVariableImpl.class)) {
          try {
            method.setAccessible(true);
          } catch (AccessControlException e) {

    @Mock
    private Address mockAddress;

    @Test
    @DisplayName("Address interface should define correct method signatures")
    void testInterfaceContract() {
        // Given
        Address address = mockAddress;

        // When & Then - verify interface methods exist and can be called
        assertDoesNotThrow(() -> {
            address.getHostName();
            address.getHostAddress();

 * fragile because they assume that only certain methods will be called and because they often
 * implement subtleties of the API improperly.
 *
 * <p><b>Custom implementation</b>: Avoid implementing {@code ListenableFuture} from scratch. If you
 * can't get by with the standard implementations, prefer to derive a new {@code Future} instance
 * with the methods in {@link Futures} or, if necessary, to extend {@link AbstractFuture}.
 *

    ImmutableList.Builder<Callable<T>> builder = ImmutableList.builder();
    for (Callable<T> task : tasks) {
      builder.add(wrapTask(task));
    }
    return builder.build();
  }

  // These methods wrap before delegating.
  @Override
  public final void execute(Runnable command) {
    delegate.execute(wrapTask(command));
  }

  @Override