{* ../../docs_src/events/tutorial003.py hl[14:19] *}

함수의 첫 번째 부분, 즉 `yield` 이전의 코드는 애플리케이션이 시작되기 **전에** 실행됩니다.

그리고 `yield` 이후의 부분은 애플리케이션이 완료된 후 **나중에** 실행됩니다.

### 비동기 컨텍스트 매니저

함수를 확인해보면, `@asynccontextmanager`로 장식되어 있습니다.

이것은 함수를 "**비동기 컨텍스트 매니저**"라고 불리는 것으로 변환시킵니다.

{* ../../docs_src/events/tutorial003.py hl[1,13] *}

 * events fired during collection.
 *
 * @since 3.9.0
 */
class ReverseTreeRepositoryListener extends AbstractRepositoryListener {
    @Override
    public void artifactResolved(RepositoryEvent event) {
        requireNonNull(event, "event cannot be null");

        if (!isLocalRepositoryArtifactOrMissing(event.getSession(), event.getArtifact())) {
            return;
        }

 - CallEnd
 
### Cache Miss

Under a cache miss the normal request events are seen but an additional event shows the presence of the cache.
Cache Miss will be typical if the item has not been read from the network, is uncacheable, or is past it's 
lifetime based on Response cache headers.

 - CallStart 
 - **CacheMiss**
 - ProxySelectStart
 - ... Standard Events ...
 - CallEnd
        
### Conditional Cache Hit
 

	}
	return true, nil
}

// send - sends an event to the mqtt.
func (target *MQTTTarget) send(eventData event.Event) error {
	objectName, err := url.QueryUnescape(eventData.S3.Object.Key)
	if err != nil {
		return err
	}
	key := eventData.S3.Bucket.Name + "/" + objectName

	data, err := json.Marshal(event.Log{EventName: eventData.EventName, Key: key, Records: []event.Event{eventData}})
	if err != nil {
		return err
	}

	}
	return err
}

// send - sends an event to the webhook.
func (target *WebhookTarget) send(eventData event.Event) error {
	objectName, err := url.QueryUnescape(eventData.S3.Object.Key)
	if err != nil {
		return err
	}
	key := eventData.S3.Bucket.Name + "/" + objectName

	data, err := json.Marshal(event.Log{EventName: eventData.EventName, Key: key, Records: []event.Event{eventData}})
	if err != nil {
		return err
	}

     * @param event The event to fire, must not be {@code null}.
     */
    void fire(ModelBuildingListener listener, ModelBuildingEvent event);

    ModelBuildingEventCatapult BUILD_EXTENSIONS_ASSEMBLED = new ModelBuildingEventCatapult() {
        @Override
        public void fire(ModelBuildingListener listener, ModelBuildingEvent event) {
            listener.buildExtensionsAssembled(event);
        }
    };

     */
    NODE_AVAILABLE(7);

    private final int value;

    /**
     * Creates a new WitnessEventType with the specified value.
     *
     * @param value the numeric event type value
     */
    WitnessEventType(int value) {
        this.value = value;
    }

    /**
     * Gets the numeric event type value.
     *
     * @return the event type value
     */
    public int getValue() {

		} else {
			var data []byte
			if data, err = json.Marshal(struct{ Records []event.Event }{[]event.Event{eventData}}); err != nil {
				return err
			}

			_, err = target.updateStmt.Exec(key, data)
		}

		return err
	}

	if target.args.Format == event.AccessFormat {
		eventTime, err := time.Parse(event.AMZTimeFormat, eventData.EventTime)
		if err != nil {
			return err
		}

    /**
     * Notifies the listener that the model has been constructed to the extent where build extensions can be processed.
     *
     * @param event The details about the event.
     */
    void buildExtensionsAssembled(ModelBuildingEvent event);

        ForkedProjectStarted,
        ForkedProjectSucceeded,
        ForkedProjectFailed,
    }

    /**
     * Gets the type of the event.
     *
     * @return The type of the event, never {@code null}.
     */
    Type getType();

    /**
     * Gets the session from which this event originates.
     *
     * @return The current session, never {@code null}.
     */
    MavenSession getSession();

    /**