*     indicates that the elements' <i>natural ordering</i> should be used.
   */
  @SuppressWarnings("unchecked")
  public static <E extends @Nullable Object> TreeMultiset<E> create(
      @CheckForNull Comparator<? super E> comparator) {
    return (comparator == null)
        ? new TreeMultiset<E>((Comparator) Ordering.natural())
        : new TreeMultiset<E>(comparator);
  }

  /**

    MapMakerInternalMap<Object, Object, ?, ?> map =
        makeMap(createMapMaker().concurrencyLevel(1).weakValues());
    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<? extends InternalEntry<Object, Object, ?>> table = segment.table;

 * @author Sverre Sundsdal
 */
@GwtCompatible(emulated = true)
@ElementTypesAreNonnullByDefault
public class MinMaxPriorityQueueTest extends TestCase {
  private static final Ordering<Integer> SOME_COMPARATOR = Ordering.<Integer>natural().reverse();

  @J2ktIncompatible
  @GwtIncompatible // suite
  public static Test suite() {
    TestSuite suite = new TestSuite();

    MapMakerInternalMap<Object, Object, ?, ?> map =
        makeMap(createMapMaker().concurrencyLevel(1).weakValues());
    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<? extends InternalEntry<Object, Object, ?>> table = segment.table;

   * {@inheritDoc}
   *
   * <p>The iterator generated by the returned collection traverses the values in the order they
   * were added to the multimap. Because the values may have duplicates and follow the insertion
   * ordering, this method returns a {@link List}, instead of the {@link Collection} specified in
   * the {@link ListMultimap} interface.
   */
  @Override
  public List<V> values() {
    return (List<V>) super.values();
  }

    testers.add(ListToArrayTester.class);
    return testers;
  }

  /**
   * Specifies {@link CollectionFeature#KNOWN_ORDER} for all list tests, since lists have an
   * iteration ordering corresponding to the insertion order.
   */
  @Override
  public TestSuite createTestSuite() {
    withFeatures(KNOWN_ORDER);
    return super.createTestSuite();
  }

  @Override

    putEdge(N2, N1);
    assertThat(graph.outDegree(N1)).isEqualTo(3);
  }

  // Stable order tests

  // Note: Stable order means that the ordering doesn't change between iterations and versions.
  // Ideally, the ordering in test should never be updated.
  @Test
  public void stableIncidentEdgeOrder_edges_returnsInStableOrder() {

    super(true, true, true, true, true);
  }

  @Override
  protected SortedMap<String, Integer> makeEmptyMap() {
    return new SimpleForwardingSortedMap<>(
        new TreeMap<String, Integer>(Ordering.<String>natural().nullsFirst()));
  }

  @Override
  protected SortedMap<String, Integer> makePopulatedMap() {
    final SortedMap<String, Integer> sortedMap = makeEmptyMap();
    sortedMap.put("one", 1);

  }

  @Test
  public void edgeValue_undirected_mismatch() {
    graph = ValueGraphBuilder.undirected().build();
    graph.putEdgeValue(1, 2, "A");
    // Check that edgeValue() throws on each possible ordering of an ordered EndpointPair
    IllegalArgumentException e =
        assertThrows(
            IllegalArgumentException.class, () -> graph.edgeValue(EndpointPair.ordered(1, 2)));

  static final String EDGE_ALREADY_EXISTS = "Edge %s already exists in the graph.";
  static final String ENDPOINTS_MISMATCH =
      "Mismatch: endpoints' ordering is not compatible with directionality of the graph";

  /** Singleton edge value for {@link Graph} implementations backed by {@link ValueGraph}s. */
  enum Presence {
    EDGE_EXISTS
  }