Collections.addAll(multiset, elements);
        return multiset;
      }

      @Override
      public List<String> order(List<String> insertionOrder) {
        return Ordering.natural().sortedCopy(insertionOrder);
      }
    };
  }

  private static final String KEY = "puppies";

  ConcurrentMap<String, AtomicInteger> backingMap;
  ConcurrentHashMultiset<String> multiset;

  private static <N, V> ImmutableMap<N, GraphConnections<N, V>> getNodeConnections(
      ValueGraph<N, V> graph) {
    // ImmutableMap.Builder maintains the order of the elements as inserted, so the map will have
    // whatever ordering the graph's nodes do, so ImmutableSortedMap is unnecessary even if the
    // input nodes are sorted.
    ImmutableMap.Builder<N, GraphConnections<N, V>> nodeConnections = ImmutableMap.builder();
    for (N node : graph.nodes()) {

@ElementTypesAreNonnullByDefault
final class RegularImmutableSortedSet<E> extends ImmutableSortedSet<E> {
  static final RegularImmutableSortedSet<Comparable> NATURAL_EMPTY_SET =
      new RegularImmutableSortedSet<>(ImmutableList.<Comparable>of(), Ordering.natural());

  private final transient ImmutableList<E> elements;

  RegularImmutableSortedSet(ImmutableList<E> elements, Comparator<? super E> comparator) {
    super(comparator);
    this.elements = elements;
  }

  /**
   * Asserts that the collection under test contains exactly the given elements, respecting
   * cardinality but not order. Subclasses may override this method to provide stronger assertions,
   * e.g., to check ordering in lists, but realize that <strong>unless a test extends {@link
   * com.google.common.collect.testing.testers.AbstractListTester AbstractListTester}, a call to
   * {@code expectContents()} invokes this version</strong>.
   *

        new SynchronousQueue<Object>(),
        new ArrayBlockingQueue<Object>(10),
        new LinkedBlockingDeque<Object>(),
        new LinkedBlockingDeque<Object>(10),
        new PriorityBlockingQueue<Object>(10, Ordering.arbitrary()));
  }

  /*
   * We need to perform operations in a thread pool, even for simple cases, because the queue might
   * be a SynchronousQueue.
   */
  private ExecutorService threadPool;

                .concurrencyLevel(1)
                .ticker(ticker)
                .expireAfterAccess(1, NANOSECONDS));
    Segment<Object, Object> segment = map.segments[0];
    // TODO(fry): check recency ordering

    Object key = new Object();
    int hash = map.hash(key);
    Object value = new Object();
    AtomicReferenceArray<ReferenceEntry<Object, Object>> table = segment.table;

                .concurrencyLevel(1)
                .ticker(ticker)
                .expireAfterAccess(1, NANOSECONDS));
    Segment<Object, Object> segment = map.segments[0];
    // TODO(fry): check recency ordering

    Object key = new Object();
    int hash = map.hash(key);
    Object value = new Object();
    AtomicReferenceArray<ReferenceEntry<Object, Object>> table = segment.table;

 * invoke methods, they invoke methods on the {@code ForwardingNavigableSet}.
 *
 * <p>Each of the {@code standard} methods uses the set's comparator (or the natural ordering of the
 * elements, if there is no comparator) to test element equality. As a result, if the comparator is
 * not consistent with equals, some of the standard implementations may violate the {@code Set}
 * contract.
 *

    if (!isOrderingCompatible(endpoints)) {
      return false;
    }
    return hasEdgeConnecting(endpoints.nodeU(), endpoints.nodeV());
  }

  /**
   * Throws an IllegalArgumentException if the ordering of {@code endpoints} is not compatible with
   * the directionality of this graph.
   */
  protected final void validateEndpoints(EndpointPair<?> endpoints) {
    checkNotNull(endpoints);

    if (!isOrderingCompatible(endpoints)) {
      return false;
    }
    return hasEdgeConnecting(endpoints.nodeU(), endpoints.nodeV());
  }

  /**
   * Throws an IllegalArgumentException if the ordering of {@code endpoints} is not compatible with
   * the directionality of this graph.
   */
  protected final void validateEndpoints(EndpointPair<?> endpoints) {
    checkNotNull(endpoints);