if (!entryIterator.hasNext()) {
      return null;
    }
    Entry<E> entry = entryIterator.next();
    return Multisets.immutableEntry(entry.getElement(), entry.getCount());
  }

  @Override
  public @Nullable Entry<E> lastEntry() {
    return delegate().lastEntry();
  }

  /**
   * A sensible definition of {@link #lastEntry()} in terms of {@code

    assertEquals(1, listenerLatch.getCount());
    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());

            crawler1.awaitTermination();
            crawler2.awaitTermination();

            assertEquals(maxCount, dataService.getCount(sessionId1));
            assertEquals(maxCount, dataService.getCount(sessionId2));

            UrlQueue urlQueue;
            while ((urlQueue = urlQueueService.poll(sessionId1)) != null) {
                assertTrue(urlQueue.getUrl().startsWith(url1));

    assertEquals("Eviction notifications must be received", 10, removalListener.getCount());

    CacheTesting.expireEntries((LoadingCache<?, ?>) cache, EXPIRING_TIME, ticker);
    // ensure that no new notifications are sent
    assertEquals("Eviction notifications must be received", 10, removalListener.getCount());
  }

  public void testExpiringGet_expireAfterWrite() {
    FakeTicker ticker = new FakeTicker();

    if (!entryIterator.hasNext()) {
      return null;
    }
    Entry<E> entry = entryIterator.next();
    return Multisets.immutableEntry(entry.getElement(), entry.getCount());
  }

  @Override
  public @Nullable Entry<E> lastEntry() {
    return delegate().lastEntry();
  }

  /**
   * A sensible definition of {@link #lastEntry()} in terms of {@code

            crawler1.awaitTermination();
            crawler2.awaitTermination();

            assertEquals(maxCount, dataService.getCount(sessionId1));
            assertEquals(maxCount, dataService.getCount(sessionId2));

            UrlQueue urlQueue;
            while ((urlQueue = urlQueueService.poll(sessionId1)) != null) {
                assertTrue(urlQueue.getUrl().startsWith(url1));

            crawler1.awaitTermination();
            crawler2.awaitTermination();

            assertEquals(maxCount, dataService.getCount(sessionId1));
            assertEquals(maxCount, dataService.getCount(sessionId2));

            UrlQueue urlQueue;
            while ((urlQueue = urlQueueService.poll(sessionId1)) != null) {

    LocalCache<Object, Object> map = makeLocalCache(createCacheBuilder());
    assertEquals(0, loader.getCount());

    Object key = new Object();
    Object value = map.get(key, loader);
    assertEquals(1, loader.getCount());
    assertEquals(value, map.get(key, loader));
    assertEquals(1, loader.getCount());
  }

  public void testRecordReadOnCompute() throws ExecutionException {

    }

    @Override
    public int count(@Nullable Object element) {
      for (Entry<E> entry : entrySet()) {
        if (Objects.equals(entry.getElement(), element)) {
          return entry.getCount();
        }
      }
      return 0;
    }

    @Override
    public int add(E element, int occurrences) {
      checkArgument(occurrences >= 0);

      for (int j = 0; j < numListeners; j++) {
        list.add(listener, directExecutor());
        returnValue += listenerLatch.getCount();
      }
      list.execute();
      returnValue += listenerLatch.getCount();
    }
    return returnValue;
  }

  @Benchmark
  int executeThenAdd_singleThreaded(int reps) {
    int returnValue = 0;