.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.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
  public void lockInterruptibly() throws InterruptedException {

    // 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();

 * </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
 * object). So it is important to not call {@link #dispatch} while holding any locks. This is why

     * the type is irrelevant at runtime.
     */
    mock = mock(Cache.class);
    forward =
        new ForwardingCache<String, Boolean>() {
          @Override
          protected Cache<String, Boolean> delegate() {
            return mock;
          }
        };
  }

  public void testGetIfPresent() throws ExecutionException {
    when(mock.getIfPresent("key")).thenReturn(Boolean.TRUE);

import com.google.common.util.concurrent.ListenableFuture;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutionException;
import junit.framework.Assert;

/**
 * A simple mock implementation of {@code Runnable} that can be used for testing ListenableFutures.
 *
 * @author Nishant Thakkar
 * @since 10.0
 */
@GwtIncompatible
public class MockFutureListener implements Runnable {