* A collector for DeadEvents.
   *
   * @author cbiffle
   */
  public static class GhostCatcher {
    private final List<DeadEvent> events = new ArrayList<>();

    @Subscribe
    public void ohNoesIHaveDied(DeadEvent event) {
      events.add(event);
    }

    public List<DeadEvent> getEvents() {
      return events;
    }
  }

  private interface Callback<T> {
    void call(T t);
  }