### Question:
EmailNotifier implements Notifier, TransportListener { public void messageNotDelivered(TransportEvent event) { LOG.debug("Got messageNotDelivered event {}", event); handleFail(event); }  @Override void open(NotificationContext ctx); void messageDelivered(TransportEvent event); void messageNotDelivered(TransportEvent event); void messagePartiallyDelivered(TransportEvent event); @Override void notify(Notification notification); @Override void close(); @Override boolean isPull(); @Override List<String> getFields(); @Override NotificationContext getContext();  }### Answer:
@Test public void testMessageNotDelivered() throws Exception { }