return
				}
			}

			// All versions resulted in 'ObjectNotFound/VersionNotFound'
			if versionNotFound == len(fivs.Versions) {
				return
			}

			send(healEntryDone(entry.name))

			// Wait and proceed if there are active requests
			waitForLowHTTPReq()
		}

		// How to resolve partial results.
		resolver := metadataResolutionParams{
			dirQuorum: 1,
			objQuorum: 1,
			bucket:    bucket,

In diesem Fall schreibt die Taskfunktion in eine Datei (den Versand einer E-Mail simulierend).

Und da der Schreibvorgang nicht `async` und `await` verwendet, definieren wir die Funktion mit normalem `def`:

{* ../../docs_src/background_tasks/tutorial001_py39.py hl[6:9] *}

## Den Hintergrundtask hinzufügen { #add-the-background-task }

            settingsBuilder.put("http.cors.allow-origin", "*");
            settingsBuilder.put("discovery.type", "single-node");
        }).build(newConfigs().clusterName(clusterName).numOfNode(1));

        // wait for yellow status
        runner.ensureYellow();

        System.setProperty(FesenClient.HTTP_ADDRESS, "localhost:" + runner.node().settings().get("http.port", "9201"));

        super.setUp();

        // logging

    try {
      exchange.writeRequestHeaders(request)

      if (hasRequestBody) {
        // If there's a "Expect: 100-continue" header on the request, wait for a "HTTP/1.1 100
        // Continue" response before transmitting the request body. If we don't get that, return
        // what we did get (such as a 4xx response) without ever transmitting the request body.

		if t.updating.TryLock() {
			go func() {
				defer t.updating.Unlock()
				t.update(context.Background())
			}()
		}
		return *v, nil
	}

	// Get lock. Either we get it or we wait for it.
	t.updating.Lock()
	defer t.updating.Unlock()

	if time.Since(time.UnixMilli(t.lastUpdateMs.Load())) < ttl {
		// There is a new value, release lock and return it.
		if v = t.val.Load(); v != nil {

				// Number of probes.
				// ~ cat /proc/sys/net/ipv4/tcp_keepalive_probes (defaults to 9, we reduce it to 5)
				_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, syscall.TCP_KEEPCNT, 5)

				// Wait time after successful probe in seconds.
				// ~ cat /proc/sys/net/ipv4/tcp_keepalive_intvl (defaults to 75 secs, we reduce it to 15 secs)
				_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, syscall.TCP_KEEPINTVL, 15)
			}

            // Test implementation
        }

        public boolean waitForNotification(long timeoutMs) throws InterruptedException {
            return notificationLatch.await(timeoutMs, TimeUnit.MILLISECONDS);
        }

        public WitnessNotification getLastNotification() {
            return lastNotification;
        }
    }

    /**

        // Create an expired handle
        HandleInfo expiredHandle = new HandleInfo("/test/file.txt", new HandleGuid(), new byte[16], HandleType.DURABLE_V2, 100, // 100ms timeout
                null);

        // Wait for expiration
        Thread.sleep(150);

        CompletableFuture<HandleInfo> future = reconnector.reconnectHandle(expiredHandle, new IOException("Network error"));

	}

	// If we have too many waiting, reject this at once.
	if l.waitMutex.Load() > lockMutexWaitLimit {
		l.locksOverloaded.Add(1)
		return false, nil
	}
	// Wait for mutex
	defer l.getMutex()()
	if ctx.Err() != nil {
		return false, ctx.Err()
	}
	if !l.canTakeLock(args.Resources...) {
		// Not all locks can be taken on resources,
		// reject it completely.

```Python
with open("file.txt") as file:
    file.read()
```
최근 버전의 파이썬에서는 **비동기 컨텍스트 매니저**도 있습니다. 이를 `async with`와 함께 사용합니다:

```Python
async with lifespan(app):
    await do_stuff()
```

컨텍스트 매니저나 위와 같은 비동기 컨텍스트 매니저를 만들면, `with` 블록에 들어가기 전에 `yield` 이전의 코드가 실행되고, `with` 블록을 벗어난 후에는 `yield` 이후의 코드가 실행됩니다.

위의 코드 예제에서는 직접 사용하지 않고, FastAPI에 전달하여 사용하도록 합니다.