.add(new Striped.SmallLazyStriped<ReadWriteLock>(50, READ_WRITE_LOCK_SUPPLIER))
        .add(new Striped.SmallLazyStriped<ReadWriteLock>(64, READ_WRITE_LOCK_SUPPLIER))
        .add(new Striped.LargeLazyStriped<ReadWriteLock>(50, READ_WRITE_LOCK_SUPPLIER))
        .add(new Striped.LargeLazyStriped<ReadWriteLock>(64, READ_WRITE_LOCK_SUPPLIER))
        .add(new Striped.SmallLazyStriped<Lock>(50, LOCK_SUPPLER))

        .add(new Striped.SmallLazyStriped<ReadWriteLock>(50, READ_WRITE_LOCK_SUPPLIER))
        .add(new Striped.SmallLazyStriped<ReadWriteLock>(64, READ_WRITE_LOCK_SUPPLIER))
        .add(new Striped.LargeLazyStriped<ReadWriteLock>(50, READ_WRITE_LOCK_SUPPLIER))
        .add(new Striped.LargeLazyStriped<ReadWriteLock>(64, READ_WRITE_LOCK_SUPPLIER))
        .add(new Striped.SmallLazyStriped<Lock>(50, LOCK_SUPPLER))

import java.util.concurrent.TimeUnit;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.Lock;

/** Forwarding wrapper around a {@code Lock}. */
@J2ktIncompatible
@ElementTypesAreNonnullByDefault
abstract class ForwardingLock implements Lock {
  abstract Lock delegate();

  @Override
  public void lock() {
    delegate().lock();
  }

  @Override

    // NPE on null listener, so we propagate that contract up into the add method as well.
    checkNotNull(runnable, "Runnable was null.");
    checkNotNull(executor, "Executor was null.");

    // Lock while we check state. We must maintain the lock while adding the new pair so that
    // another thread can't run the list out from under us. We only add to the list if we have not
    // yet started execution.
    synchronized (this) {

    }

    @Override
    public E element() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.element();
    }

    @Override
    public Iterator<E> iterator() {
      // We explicitly don't lock for iterator()
      assertFalse(Thread.holdsLock(mutex));
      return delegate.iterator();
    }

    @Override
    public int size() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.size();

    }

    @Override
    public E element() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.element();
    }

    @Override
    public Iterator<E> iterator() {
      // We explicitly don't lock for iterator()
      assertFalse(Thread.holdsLock(mutex));
      return delegate.iterator();
    }

    @Override
    public int size() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.size();

    }

    @Override
    public E element() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.element();
    }

    @Override
    public Iterator<E> iterator() {
      // We explicitly don't lock for iterator()
      assertFalse(Thread.holdsLock(mutex));
      return delegate.iterator();
    }

    @Override
    public int size() {
      assertTrue(Thread.holdsLock(mutex));
      return delegate.size();

 *   <li>It is easy for the user to ensure that listeners are never invoked while holding locks.
 * </ul>
 *
 * The last point is subtle. Often the observable object will be managing its own internal state
 * using a lock, however it is dangerous to dispatch listeners while holding a lock because they
 * might run on the {@code directExecutor()} or be otherwise re-entrant (call back into your

   * then:
   *
   * <ul>
   *   <li>{@code isDone()} must return {@code true}
   *   <li>{@code isCancelled()} must return {@code false}
   *   <li>{@code get()} must not block, and it must throw an {@code ExecutionException} with the
   *       return value of this method as its cause
   * </ul>
   */
  public static
      Throwable tryInternalFastPathGetFailure(InternalFutureFailureAccess future) {

    assertFalse(task.isDone());
    assertFalse(task.isCancelled());

    // Start the task to put it in the RUNNING state.  Have to use a separate
    // thread because the task will block on the task latch after unblocking
    // the run latch.
    exec.execute(task);
    runLatch.await();
    assertEquals(1, listenerLatch.getCount());
    assertFalse(task.isDone());
    assertFalse(task.isCancelled());