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);

        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;

   * build-system quirks.
   */
  private @interface GwtTransient {}

  /**
   * Compares strings in natural order except that null comes immediately before a given value. This
   * works better than Ordering.natural().nullsFirst() because, if null comes before all other
   * values, it lies outside the submap/submultiset ranges we test, and the variety of tests that
   * exercise null handling fail on those subcollections.
   */

          // but it would help with some of these lock ordering issues.
          scheduleFailure = e;
          toReturn = new FutureAsCancellable(immediateCancelledFuture());
        } finally {
          lock.unlock();
        }
        // Call notifyFailed outside the lock to avoid lock ordering issues.
        if (scheduleFailure != null) {
          service.notifyFailed(scheduleFailure);

    // does not impact recency ordering
    if (key == null) {
      return false;
    }
    int hash = hash(key);
    return segmentFor(hash).containsKey(key, hash);
  }

  @Override
  public boolean containsValue(@CheckForNull Object value) {
    // does not impact recency ordering
    if (value == null) {
      return false;
    }

        }

        return maximals.getFirst();
    }

    /**
     * Determines which method signature (represented by a class array) is more
     * specific. This defines a partial ordering on the method signatures.
     *
     * @param c1 first signature to compare
     * @param c2 second signature to compare
     * @return MORE_SPECIFIC if c1 is more specific than c2, LESS_SPECIFIC if

      return key;
    } else if (oldEntryForKey != null && !force) {
      throw new IllegalArgumentException("key already present: " + key);
    }

    /*
     * The ordering here is important: if we deleted the key entry and then the value entry,
     * the key entry's prev or next pointer might point to the dead value entry, and when we

        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;

 * average, in the marking phase, not {@code 5.0} as in {@code java.util.HashSet}.
 *
 * <p>If there are no removals, then {@link #iterator iteration} order is the same as insertion
 * order. Any removal invalidates any ordering guarantees.
 *
 * <p>This class should not be assumed to be universally superior to {@code java.util.HashSet}.
 * Generally speaking, this class reduces object allocation and memory consumption at the price of

   */
  private static final class ThreadConfinedTaskQueue {
    /**
     * This field is only used for identity comparisons with the current thread. Field assignments
     * are atomic, but do not provide happens-before ordering; however:
     *
     * <ul>
     *   <li>If this field's value == currentThread, we know that it's up to date, because write
     *       operations in a thread always happen-before subsequent read operations in the same