{* ../../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] *}

        dispatcher.onEvent(event);
        delegate.artifactInstalling(event);
    }

    @Override
    public void artifactResolved(RepositoryEvent event) {
        dispatcher.onEvent(event);
        delegate.artifactResolved(event);
    }

    @Override
    public void artifactResolving(RepositoryEvent event) {
        dispatcher.onEvent(event);
        delegate.artifactResolving(event);
    }

    @Override

	}
	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
	}

		} 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
		}

     * @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() {

    /**
     * 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);

}

// send - sends an event to the Nats.
func (target *NATSTarget) 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
	}

		} 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
		}