*
   * @return the source of this event.
   */
  public Object getSource() {
    return source;
  }

  /**
   * Returns the wrapped, 'dead' event, which the system was unable to deliver to any registered
   * subscriber.
   *
   * @return the 'dead' event that could not be delivered.
   */
  public Object getEvent() {
    return event;
  }

  @Override
  public String toString() {