synchronized(this@DiskLruCache) {
          // If the cache is closed, truncate the iterator.
          if (closed) return false

          while (delegate.hasNext()) {
            nextSnapshot = delegate.next()?.snapshot() ?: continue
            return true
          }
        }

        return false
      }

      override fun next(): Snapshot {

    private final SuccessorsFunction<Character> delegate;
    final Multiset<Character> requestedNodes = HashMultiset.create();

    RequestSavingGraph(SuccessorsFunction<Character> delegate) {
      this.delegate = checkNotNull(delegate);
    }

    @Override
    public Iterable<? extends Character> successors(Character node) {
      requestedNodes.add(node);
      return delegate.successors(node);
    }
  }

    private final SuccessorsFunction<Character> delegate;
    final Multiset<Character> requestedNodes = HashMultiset.create();

    RequestSavingGraph(SuccessorsFunction<Character> delegate) {
      this.delegate = checkNotNull(delegate);
    }

    @Override
    public Iterable<? extends Character> successors(Character node) {
      requestedNodes.add(node);
      return delegate.successors(node);
    }
  }

  @Override
  public SortedMultiset<E> tailMultiset(E fromElement, BoundType boundType) {
    return forwardMultiset().headMultiset(fromElement, boundType).descendingMultiset();
  }

  @Override
  protected Multiset<E> delegate() {
    return forwardMultiset();
  }

  @Override
  public SortedMultiset<E> descendingMultiset() {
    return forwardMultiset();
  }

  @Override
  public @Nullable Entry<E> firstEntry() {

    String concurrentPackage = SettableFuture.class.getPackage().getName();
    ClassLoader classLoader = AggregateFutureStateFallbackAtomicHelperTest.class.getClassLoader();
    // we delegate to the current classloader so both loaders agree on classes like TestCase
    return new URLClassLoader(ClassPathUtil.getClassPathUrls(), classLoader) {
      @Override

              @Override
              protected SortedMap<String, String> create(Entry<String, String>[] entries) {
                NavigableMap<String, String> delegate = populate(new TreeMap<>(), entries);
                return Collections.synchronizedNavigableMap(delegate);
              }
            })
        .named("synchronizedNavigableMap/TreeMap, natural")
        .withFeatures(
            MapFeature.GENERAL_PURPOSE,

    MinMaxPriorityQueue<T> mmHeap;

    public InvertedMinMaxPriorityQueue(Comparator<T> comparator) {
      mmHeap = MinMaxPriorityQueue.orderedBy(comparator).create();
    }

    @Override
    protected Queue<T> delegate() {
      return mmHeap;
    }

    @Override
    public @Nullable T poll() {
      return mmHeap.pollLast();
    }
  }

  public enum HeapType {
    MIN_MAX {
      @Override

    private final Map<String, Object> parent;

    /**
     * Constructor that creates a DocMap wrapping the given parent map.
     *
     * @param parent the map to wrap and delegate operations to
     */
    public DocMap(final Map<String, Object> parent) {
        this.parent = parent;
    }

    /**
     * Returns the number of key-value mappings in this map.
     *

    String concurrentPackage = SettableFuture.class.getPackage().getName();
    ClassLoader classLoader = AbstractFutureFallbackAtomicHelperTest.class.getClassLoader();
    // we delegate to the current classloader so both loaders agree on classes like TestCase
    return new URLClassLoader(ClassPathUtil.getClassPathUrls(), classLoader) {
      @Override

    assertTrue(multimap.replaceValues("bar", asList(2, 4)) instanceof RandomAccess);
  }

  /** Test throwing ConcurrentModificationException when a sublist's ancestor's delegate changes. */
  public void testSublistConcurrentModificationException() {
    ListMultimap<String, Integer> multimap = create();
    multimap.putAll("foo", asList(1, 2, 3, 4, 5));
    List<Integer> list = multimap.get("foo");