*/
@GwtCompatible
public final class SettableFuture<V extends @Nullable Object>
    extends AbstractFuture.TrustedFuture<V> {
  /**
   * Creates a new {@code SettableFuture} that can be completed or cancelled by a later method call.
   */
  public static <V extends @Nullable Object> SettableFuture<V> create() {
    return new SettableFuture<>();
  }

  @CanIgnoreReturnValue
  @Override

 */
@GwtCompatible
public final class SettableFuture<V extends @Nullable Object>
    extends AbstractFuture.TrustedFuture<V> {
  /**
   * Creates a new {@code SettableFuture} that can be completed or cancelled by a later method call.
   */
  public static <V extends @Nullable Object> SettableFuture<V> create() {
    return new SettableFuture<>();
  }

  @CanIgnoreReturnValue
  @Override

  public void testSameThreadSuccess() {
    SettableFuture<String> f = SettableFuture.create();
    MockCallback callback = new MockCallback("foo");
    addCallback(f, callback, directExecutor());
    f.set("foo");
  }

  public void testExecutorSuccess() {
    CountingSameThreadExecutor ex = new CountingSameThreadExecutor();
    SettableFuture<String> f = SettableFuture.create();
    MockCallback callback = new MockCallback("foo");

    SettableFuture<String> future = SettableFuture.create();
    SettableFuture<String> nested = SettableFuture.create();
    assertTrue(future.setFuture(nested));
    // Later attempts to set the future should return false.
    assertFalse(future.set("x"));
    assertFalse(future.setException(new Exception("bar")));
    assertFalse(future.setFuture(SettableFuture.<String>create()));

  private Class<?> settableFutureClass;
  private Class<?> abstractFutureClass;

  @Override
  protected void setUp() throws Exception {
    // Load the "normal" copy of SettableFuture and related classes.
    SettableFuture<?> unused = SettableFuture.create();
    // Hack to load AbstractFuture et. al. in a new classloader so that it re-reads the cancellation

  private Class<?> settableFutureClass;
  private Class<?> abstractFutureClass;

  @Override
  protected void setUp() throws Exception {
    // Load the "normal" copy of SettableFuture and related classes.
    SettableFuture<?> unused = SettableFuture.create();
    // Hack to load AbstractFuture et. al. in a new classloader so that it re-reads the cancellation

  public void testSameThreadSuccess() {
    SettableFuture<String> f = SettableFuture.create();
    MockCallback callback = new MockCallback("foo");
    addCallback(f, callback, directExecutor());
    f.set("foo");
  }

  public void testExecutorSuccess() {
    CountingSameThreadExecutor ex = new CountingSameThreadExecutor();
    SettableFuture<String> f = SettableFuture.create();
    MockCallback callback = new MockCallback("foo");

    unused = null; // Hint to the JIT that unused is unreachable
    GcFinalization.await(latch);
    assertEquals(0, latch.getCount());
  }

  public void testAwaitDone_future() {
    SettableFuture<@Nullable Void> future = SettableFuture.create();
    Object unused =
        new Object() {
          @SuppressWarnings({"removal", "Finalize"}) // b/260137033
          @Override
          protected void finalize() {

    unused = null; // Hint to the JIT that unused is unreachable
    GcFinalization.await(latch);
    assertEquals(0, latch.getCount());
  }

  public void testAwaitDone_future() {
    SettableFuture<@Nullable Void> future = SettableFuture.create();
    Object unused =
        new Object() {
          @SuppressWarnings({"removal", "Finalize"}) // b/260137033
          @Override
          protected void finalize() {

 *   <li>If you manually call {@link java.util.concurrent.FutureTask#set} or a similar method,
 *       create a {@link SettableFuture} instead. (If your needs are more complex, you may prefer
 *       {@link AbstractFuture}.)
 * </ul>
 *
 * <p><b>Test doubles</b>: If you need a {@code ListenableFuture} for your test, try a {@link
 * SettableFuture} or one of the methods in the {@link Futures#immediateFuture Futures.immediate*}