@CanIgnoreReturnValue
    @Override
    public final V get() throws InterruptedException, ExecutionException {
      return super.get();
    }

    @CanIgnoreReturnValue
    @Override
    public final V get(long timeout, TimeUnit unit)
        throws InterruptedException, ExecutionException, TimeoutException {
      return super.get(timeout, unit);
    }

    @Override
    public final boolean isDone() {

  private static final class UnsafeAtomicHelper extends AtomicHelper {
    static final sun.misc.Unsafe UNSAFE;
    static final long LISTENERS_OFFSET;
    static final long WAITERS_OFFSET;
    static final long VALUE_OFFSET;
    static final long WAITER_THREAD_OFFSET;
    static final long WAITER_NEXT_OFFSET;

    static {
      sun.misc.Unsafe unsafe = null;
      try {