// A String -- an event for which no one has registered.
    bus.post(EVENT);

    List<DeadEvent> events = catcher.getEvents();
    assertEquals("One dead event should be delivered.", 1, events.size());
    assertEquals("The dead event should wrap the original event.", EVENT, events.get(0).getEvent());
  }

  public void testDeadEventPosting() {
    GhostCatcher catcher = new GhostCatcher();

    // A String -- an event for which no one has registered.
    bus.post(EVENT);

    List<DeadEvent> events = catcher.getEvents();
    assertEquals("One dead event should be delivered.", 1, events.size());
    assertEquals("The dead event should wrap the original event.", EVENT, events.get(0).getEvent());
  }

  public void testDeadEventPosting() {
    GhostCatcher catcher = new GhostCatcher();

    }

    /*
     * 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
     * put the new entry in the key entry's position in iteration order, it might invalidate
     * the linked list.
     */

    if (oldEntryForValue != null) {

  `So you did, old fellow!' said the others.

  `We must burn the house down!' said the Rabbit's voice; and
Alice called out as loud as she could, `If you do.  I'll set
Dinah at you!'

  There was a dead silence instantly, and Alice thought to
herself, `I wonder what they WILL do next!  If they had any
sense, they'd take the roof off.'  After a minute or two, they
began moving about again, and Alice heard the Rabbit say, `A

                            "c", (Collection<String>) ImmutableSortedSet.of("carl", "carol")),
                        Helpers.mapEntry(
                            "d", (Collection<String>) ImmutableSortedSet.of("david", "dead")),
                        Helpers.mapEntry(
                            "e", (Collection<String>) ImmutableSortedSet.of("eric", "elaine")));
                  }

                  @SuppressWarnings("unchecked")

    /**
     * Returns true if this reference contains an active value, meaning one that is still considered
     * present in the cache. Active values consist of live values, which are returned by cache
     * lookups, and dead values, which have been evicted but awaiting removal. Non-active values
     * consist strictly of loading values, though during refresh a value may be both active and
     * loading.
     */
    boolean isActive();
  }

                            "c", (Collection<String>) ImmutableSortedSet.of("carl", "carol")),
                        Helpers.mapEntry(
                            "d", (Collection<String>) ImmutableSortedSet.of("david", "dead")),
                        Helpers.mapEntry(
                            "e", (Collection<String>) ImmutableSortedSet.of("eric", "elaine")));
                  }

                  @SuppressWarnings("unchecked")

 * worry about being reentrant, unless also called from outside the EventBus.
 *
 * <h2>Dead Events</h2>
 *
 * <p>If an event is posted, but no registered subscribers can accept it, it is considered "dead."
 * To give the system a second chance to handle dead events, they are wrapped in an instance of
 * {@link DeadEvent} and reposted.
 *

  `So you did, old fellow!' said the others.

  `We must burn the house down!' said the Rabbit's voice; and
Alice called out as loud as she could, `If you do.  I'll set
Dinah at you!'

  There was a dead silence instantly, and Alice thought to
herself, `I wonder what they WILL do next!  If they had any
sense, they'd take the roof off.'  After a minute or two, they
began moving about again, and Alice heard the Rabbit say, `A

    /**
     * Returns true if this reference contains an active value, meaning one that is still considered
     * present in the cache. Active values consist of live values, which are returned by cache
     * lookups, and dead values, which have been evicted but awaiting removal. Non-active values
     * consist strictly of loading values, though during refresh a value may be both active and
     * loading.
     */
    boolean isActive();
  }