# 이 데코레이터가 자기에게 매긴 계약
  FailOpenNotificationProvider.java:7 /**
  FailOpenNotificationProvider.java:8  * Fail-open decorator: a provider failure is logged (no payload/PII) and swallowed so a
  FailOpenNotificationProvider.java:9  * notification — a side-effect — never fails the core use case. Applied centrally by
  FailOpenNotificationProvider.java:10  * NotificationConfig.
  FailOpenNotificationProvider.java:11  */

# 실패 경로 : catch 안에서 실패 로그를 부른다
  FailOpenNotificationProvider.java:35   @Override
  FailOpenNotificationProvider.java:36   public void send(Notification notification) {
  FailOpenNotificationProvider.java:37     try {
  FailOpenNotificationProvider.java:38       delegate.send(notification);
  FailOpenNotificationProvider.java:39       dependencyLogger.logSuccess(delegate.providerId(), DEPENDENCY_TYPE, "send");
  FailOpenNotificationProvider.java:40     } catch (Exception ex) {
  FailOpenNotificationProvider.java:41       // fail-open: observe (no payload/PII), do not fail the core use case.
  FailOpenNotificationProvider.java:42       dependencyLogger.logFailure(delegate.providerId(), DEPENDENCY_TYPE, "send", ex);
  FailOpenNotificationProvider.java:43     }
  FailOpenNotificationProvider.java:44   }
  FailOpenNotificationProvider.java:45 }

# 메시징 쪽의 같은 자리 : catch 안도 observeQuietly 를 거친다
  OutboundMessagePublisher.java:26   @Override
  OutboundMessagePublisher.java:27   public void publish(OutboundMessage message) {
  OutboundMessagePublisher.java:28     // The send and the observation are separate steps because they used to share a try block: a
  OutboundMessagePublisher.java:29     // logger that threw after a successful send was caught by the same catch and reported as a
  OutboundMessagePublisher.java:30     // publish failure. The broker had accepted the message; the only thing that failed was the
  OutboundMessagePublisher.java:31     // record of it, and the two must not be confusable.
  OutboundMessagePublisher.java:32     boolean sent = false;
  OutboundMessagePublisher.java:33     try {
  OutboundMessagePublisher.java:34       broker.send(message);
  OutboundMessagePublisher.java:35       sent = true;
  OutboundMessagePublisher.java:36     } catch (Exception ex) {
  OutboundMessagePublisher.java:37       // fail-open: observe with correlationId, delegate durability to outbox/retry,
  OutboundMessagePublisher.java:38       // do NOT propagate — the core use case must still succeed.
  OutboundMessagePublisher.java:39       observeQuietly(
  OutboundMessagePublisher.java:40           () -> dependencyLogger.logFailure(broker.brokerId(), DEPENDENCY_TYPE, "publish", ex));
  OutboundMessagePublisher.java:41     }
  OutboundMessagePublisher.java:42     if (sent) {
  OutboundMessagePublisher.java:43       observeQuietly(
  OutboundMessagePublisher.java:44           () -> dependencyLogger.logSuccess(broker.brokerId(), DEPENDENCY_TYPE, "publish"));
  OutboundMessagePublisher.java:45     }
  OutboundMessagePublisher.java:46   }
  OutboundMessagePublisher.java:48   /**
  OutboundMessagePublisher.java:49    * Runs an observation, absorbing whatever it throws.
  OutboundMessagePublisher.java:50    *
  OutboundMessagePublisher.java:51    * <p>Diagnostics are non-authoritative. An appender that is out of disk must not change what the
  OutboundMessagePublisher.java:52    * caller believes about the broker.
  OutboundMessagePublisher.java:53    */
  OutboundMessagePublisher.java:54   private static void observeQuietly(Runnable observation) {
  OutboundMessagePublisher.java:55     try {
  OutboundMessagePublisher.java:56       observation.run();
  OutboundMessagePublisher.java:57     } catch (RuntimeException ignored) {
  OutboundMessagePublisher.java:58       // Nothing to report it to: the reporter is what failed.
  OutboundMessagePublisher.java:59     }
  OutboundMessagePublisher.java:60   }

# 그 데코레이터를 부르는 팬아웃 루프
  RoutingNotifier.java:112   @Override
  RoutingNotifier.java:113   public void notify(Channel channel, String route, Notification notification) {
  RoutingNotifier.java:114     List<String> providerIds = resolveRoute(channel, route);
  RoutingNotifier.java:115     Map<String, FailOpenNotificationProvider> channelRegistry =
  RoutingNotifier.java:116         registry.getOrDefault(channel, Map.of());
  RoutingNotifier.java:117     // FailOpenNotificationProvider.send declares no throws — no try/catch needed.
  RoutingNotifier.java:118     // Individual provider failures are observed (logged) inside the decorator
  RoutingNotifier.java:119     // and never propagated, so one failure does not block remaining fan-out sends.
  RoutingNotifier.java:120     for (String providerId : providerIds) {
  RoutingNotifier.java:121       channelRegistry.get(providerId).send(notification);
  RoutingNotifier.java:122     }
  RoutingNotifier.java:123   }

# 위임 제공자가 던지는 경로에 로거 예외를 겹쳤을 때
    probe:26  if (n.equals("warn")) {
    probe:29  throw new IllegalStateException("the appender is out of disk");
    probe:56  throw new IllegalStateException("provider is down");
    probe:65  new FailOpenNotificationProvider(failing(), new FailOpenDependencyLogger(logger(warnThrows)));
    probe:70  p.send(null);
    probe:71  } catch (RuntimeException ex) {
  위임 제공자가 던지는 경로 (fail-open 이 삼켜야 하는 경우)
    실패 로거가 정상일 때               debug 0 · warn 1 · 호출자에게 나간 예외 없음
      그 예외가 제공자 예외를 달고 있는가 : cause=없음 · suppressed=0
    실패 로거도 던질 때                debug 0 · warn 1 · 호출자에게 나간 예외 IllegalStateException: the appender is out of disk
      그 예외가 제공자 예외를 달고 있는가 : cause=없음 · suppressed=0

# 그 경로를 고정하는 시험이 있는가
  알림 모듈에서 Proxy.newProxyInstance 로 로거를 만드는 자리 : 0 개
  메시징 모듈에서 같은 자리 : 1 개
  이 데코레이터를 조립하는 시험이 던지게 만드는 대상 :
    NotificationAdapterTest.java:79  throw new RuntimeException("provider-failure");
    RoutingNotifierTest.java:130  throw new RuntimeException("provider-failure");