/**
   * Returns an immutable map containing the same entries as {@code map}. If {@code map} somehow
   * contains entries with duplicate keys (for example, if it is a {@code SortedMap} whose
   * comparator is not <i>consistent with equals</i>), the results of this method are undefined.
   *
   * <p><b>Note:</b> Despite what the method name suggests, if {@code map} is an {@code
   * ImmutableClassToInstanceMap}, no copy will actually be performed.

 *
 * <p>Each of the {@code standard} methods, where appropriate, 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.
 *
 * <p>The {@code standard} methods and the collection views they return are not guaranteed to be

   * without grabbing the lock.
   *
   * <p>To update this field correctly the lock must be held to guarantee that the state is
   * consistent.
   */
  private volatile StateSnapshot snapshot = new StateSnapshot(NEW);

  /** Constructor for use by subclasses. */
  protected AbstractService() {}

  /**

   */
  public abstract N target();

  /**
   * If this {@link EndpointPair} {@link #isOrdered()} returns the {@link #source()}; otherwise,
   * returns an arbitrary (but consistent) endpoint of the origin edge.
   */
  public final N nodeU() {
    return nodeU;
  }

  /**
   * Returns the node {@link #adjacentNode(Object) adjacent} to {@link #nodeU()} along the origin

          !item.equals(NotAnInstance.EQUAL_TO_NOTHING));
      assertTrue(item + " must be Object#equals to itself", item.equals(item));
      assertEquals(
          "the Object#hashCode of " + item + " must be consistent",
          item.hashCode(),
          item.hashCode());
      if (!(item instanceof String)) {
        assertTrue(
            item + " must not be Object#equals to its Object#toString representation",

// Events have a limited retention time and triggers and messages may evolve
// with time.  Event consumers should not rely on the timing of an event
// with a given Reason reflecting a consistent underlying trigger, or the
// continued existence of events with that Reason.  Events should be
// treated as informative, best-effort, supplemental data.
message Event {
  // Standard object's metadata.

                    // Note that Firefox is fine with a sort function returning any positive or negative number, but Chrome 
                    // requires 1 or -1 specifically and ignores higher or lower values.  This sort ought to remain consistent
                    // with the sort used by AbstractAcceptedApiChangesMaintenanceTask.
                    result.acceptedApiChanges.sort((a, b) => { 

  /**
   * Returns a view of the entries stored in this cache as a thread-safe map. Modifications made to
   * the map directly affect the cache.
   *
   * <p>Iterators from the returned map are at least <i>weakly consistent</i>: they are safe for
   * concurrent use, but if the cache is modified (including by eviction) after the iterator is
   * created, it is undefined which of the changes (if any) will be reflected in that iterator.
   */

    than 63 characters between dots), and empty labels.
 *  New: Don't include the `Content-Length` header in multipart bodies. Servers must delimit
    OkHttp's request bodies using the boundary only. (This change makes OkHttp more consistent with
    browsers and other HTTP clients.)
 *  New: Drop the `tunnelProxy` argument in `MockWebServer.useHttps()`. This change only impacts
    the OkHttp 5.x API which uses the `mockwebserver3` package.

// Events have a limited retention time and triggers and messages may evolve
// with time.  Event consumers should not rely on the timing of an event
// with a given Reason reflecting a consistent underlying trigger, or the
// continued existence of events with that Reason.  Events should be
// treated as informative, best-effort, supplemental data.
message Event {
  // Standard object's metadata.