public void testSingleQuantile_median() {
    double referenceValue = REFERENCE_ALGORITHM.singleQuantile(1, 2, dataset.clone());
    for (QuantilesAlgorithm algorithm : NON_REFERENCE_ALGORITHMS) {
      assertWithMessage("Mismatch between %s and %s", algorithm, REFERENCE_ALGORITHM)
          .that(algorithm.singleQuantile(1, 2, dataset.clone()))
          .isWithin(ALLOWED_ERROR)
          .of(referenceValue);
    }
  }

    if (getList().size() != expectedList.size()) {
      fail("size mismatch: " + reportContext(expectedList));
    }
    for (int i = 0; i < expectedList.size(); i++) {
      E expected = expectedList.get(i);
      E actual = getList().get(i);
      if (expected != actual && (expected == null || !expected.equals(actual))) {
        fail("mismatch at index " + i + ": " + reportContext(expectedList));
      }
    }
  }

    if (getList().size() != expectedList.size()) {
      fail("size mismatch: " + reportContext(expectedList));
    }
    for (int i = 0; i < expectedList.size(); i++) {
      E expected = expectedList.get(i);
      E actual = getList().get(i);
      if (expected != actual && (expected == null || !expected.equals(actual))) {
        fail("mismatch at index " + i + ": " + reportContext(expectedList));
      }
    }
  }

          + "adjacentNode(node) if you already have a node, or nodeU()/nodeV() if you don't.";
  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
  }

  abstract void dispatch(Object event, Iterator<Subscriber> subscribers);

  /** Implementation of a {@link #perThreadDispatchQueue()} dispatcher. */
  private static final class PerThreadQueuedDispatcher extends Dispatcher {

    // This dispatcher matches the original dispatch behavior of EventBus.

    /** Per-thread queue of events to dispatch. */

/**
 * An {@link EventBus} that takes the Executor of your choice and uses it to dispatch events,
 * allowing dispatch to occur asynchronously.
 *
 * @author Cliff Biffle
 * @since 10.0
 */
public class AsyncEventBus extends EventBus {

  /**
   * Creates a new AsyncEventBus that will use {@code executor} to dispatch events. Assigns {@code
   * identifier} as the bus's name for logging purposes.
   *

 * using a lock, however it is dangerous to dispatch listeners while holding a lock because they
 * might run on the {@code directExecutor()} or be otherwise re-entrant (call back into your
 * object). So it is important to not call {@link #dispatch} while holding any locks. This is why
 * {@link #enqueue} and {@link #dispatch} are 2 different methods. It is expected that the decision

    queue.enqueue(incrementingEvent(counters, listener, 3));
    queue.enqueue(incrementingEvent(counters, listener, 4));
    assertEquals(0, counters.size());
    queue.dispatch();
    assertEquals(multiset(listener, 4), counters);
  }

  public void testEnqueueAndDispatch_multipleListeners() {
    Object listener1 = new Object();
    ListenerCallQueue<Object> queue = new ListenerCallQueue<>();

    queue.enqueue(incrementingEvent(counters, listener, 3));
    queue.enqueue(incrementingEvent(counters, listener, 4));
    assertEquals(0, counters.size());
    queue.dispatch();
    assertEquals(multiset(listener, 4), counters);
  }

  public void testEnqueueAndDispatch_multipleListeners() {
    Object listener1 = new Object();
    ListenerCallQueue<Object> queue = new ListenerCallQueue<>();

  private Dispatcher dispatcher;

  public void testPerThreadQueuedDispatcher() {
    dispatcher = Dispatcher.perThreadDispatchQueue();
    dispatcher.dispatch(1, integerSubscribers.iterator());

    assertThat(dispatchedSubscribers)
        .containsExactly(
            i1,
            i2,
            i3, // Integer subscribers are dispatched to first.
            s1,