* by {@code endpoints}), if one is present; otherwise, returns {@code Optional.empty()}.
   *
   * <p>If this graph is directed, the endpoints must be ordered.
   *
   * @throws IllegalArgumentException if either endpoint is not an element of this graph
   * @throws IllegalArgumentException if the endpoints are unordered and the graph is directed
   * @since 27.1
   */

    setDistinctValues(NetworkBuilder.class, NETWORK_BUILDER_A, NETWORK_BUILDER_B);
    setDistinctValues(Network.class, IMMUTABLE_NETWORK_A, IMMUTABLE_NETWORK_B);
    setDefault(EndpointPair.class, EndpointPair.ordered("A", "B"));
  }

  @Override
  public void testNulls() throws Exception {
    try {
      super.testNulls();
    } catch (AssertionError e) {

    assertEqualIgnoringOrder(asList(expected), asList(actual));
  }

  private void expectArrayContentsInOrder(List<E> expected, Object[] actual) {
    assertEquals("toArray() ordered contents: ", expected, asList(actual));
  }

  /**
   * Returns the {@link Method} instance for {@link #testToArray_isPlainObjectArray()} so that tests
   * of {@link Arrays#asList(Object[])} can suppress it with {@code

   * instead.
   *
   * @throws NullPointerException if {@code comparator} is null
   */
  public static <E> Builder<E> orderedBy(Comparator<E> comparator) {
    return new Builder<>(comparator);
  }

  /**
   * Returns a builder that creates immutable sorted sets whose elements are ordered by the reverse
   * of their natural ordering.
   */
  public static <E extends Comparable<?>> Builder<E> reverseOrder() {

    return new TreeBasedTable<>(Ordering.natural(), Ordering.natural());
  }

  /**
   * Creates an empty {@code TreeBasedTable} that is ordered by the specified comparators.
   *
   * @param rowComparator the comparator that orders the row keys
   * @param columnComparator the comparator that orders the column keys
   */
  public static <R, C, V> TreeBasedTable<R, C, V> create(

 * package.
 */
public abstract class AbstractStandardUndirectedNetworkTest extends AbstractNetworkTest {
  private static final EndpointPair<Integer> ENDPOINTS_N1N2 = EndpointPair.ordered(N1, N2);
  private static final EndpointPair<Integer> ENDPOINTS_N2N1 = EndpointPair.ordered(N2, N1);

  @After
  public void validateUndirectedEdges() {
    for (Integer node : network.nodes()) {
      new EqualsTester()
          .addEqualityGroup(

 * is not guaranteed to traverse the elements of the MonitorBasedPriorityBlockingQueue in
 * any particular order. If you need ordered traversal, consider using {@code
 * Arrays.sort(pq.toArray())}. Also, method {@code drainTo} can be used to remove some or
 * all elements in priority order and place them in another collection.
 *
 * <p>Operations on this class make no guarantees about the ordering of elements with equal

	metacacheSharePrefix = false
)

//go:generate msgp -file $GOFILE -unexported

// metacache contains a tracked cache entry.
type metacache struct {
	// do not re-arrange the struct this struct has been ordered to use less
	// space - if you do so please run https://github.com/orijtech/structslop
	// and verify if your changes are optimal.
	ended        time.Time  `msg:"end"`
	started      time.Time  `msg:"st"`

   * silently {@link #addNode(Object) add} {@code nodeU} and {@code nodeV} to the graph.
   *
   * <p>If {@code edge} already connects {@code nodeU} to {@code nodeV} (in the specified order if
   * this network {@link #isDirected()}, else in any order), then this method will have no effect.
   *
   * @return {@code true} if the network was modified as a result of this call

    setDistinctValues(NetworkBuilder.class, NETWORK_BUILDER_A, NETWORK_BUILDER_B);
    setDistinctValues(Network.class, IMMUTABLE_NETWORK_A, IMMUTABLE_NETWORK_B);
    setDefault(EndpointPair.class, EndpointPair.ordered("A", "B"));
  }

  @Override
  public void testNulls() throws Exception {
    try {
      super.testNulls();
    } catch (AssertionError e) {