int iterations = 10;
    WeakReference<Object> ref = new WeakReference<>(null);
    int expectedComputations = 0;
    for (int i = 0; i < iterations; i++) {
      // The entry should get garbage collected and recomputed.
      Object oldValue = ref.get();
      if (oldValue == null) {
        expectedComputations++;
      }
      ref = new WeakReference<>(cache.getUnchecked(1));
      oldValue = null;

      clearReferenceQueue(queueForKeys);
    }
  }

  static final class CleanupMapTask implements Runnable {
    final WeakReference<MapMakerInternalMap<?, ?, ?, ?>> mapReference;

    public CleanupMapTask(MapMakerInternalMap<?, ?, ?, ?> map) {
      this.mapReference = new WeakReference<>(map);
    }

    @Override
    public void run() {
      MapMakerInternalMap<?, ?, ?, ?> map = mapReference.get();