// Test implementation
        }

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

        public WitnessNotification getLastNotification() {
            return lastNotification;
        }
    }

    /**

    As always, in FastAPI you can combine `def` and `async def` as needed.

    If you need a refresher about when to use which, check out the section _"In a hurry?"_ in the docs about [`async` and `await`](../async.md#in-a-hurry){.internal-link target=_blank}.

9. This *path operation function* is not returning dataclasses (although it could), but a list of dictionaries with internal data.

    Wenn Sie eine Auffrischung darüber benötigen, wann welche Anwendung sinnvoll ist, lesen Sie den Abschnitt „In Eile?“ in der Dokumentation zu [`async` und `await`](../async.md#in-eile){.internal-link target=_blank}.

9. Diese *Pfadoperation-Funktion* gibt keine Datenklassen zurück (obwohl dies möglich wäre), sondern eine Liste von Dictionarys mit internen Daten.

В нашем примере фоновая задача будет вести запись в файл (симулируя отправку письма).

Так как операция записи не использует `async` и `await`, мы определим ее как обычную `def`:

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

## Добавление фоновой задачи

Les *fonctions de chemin* étant évaluées dans l'ordre, il faut s'assurer que la fonction correspondant à `/users/me` est déclarée avant celle de `/users/{user_id}` :

{* ../../docs_src/path_params/tutorial003.py hl[6,11] *}

      // We wait at most 1 second, so we don't ever turn multiple lost threads into
      // a test timeout failure.
      val waitTime = (entryTime + 1_000_000_000L - System.nanoTime())
      if (!queue.idleLatch().await(waitTime, TimeUnit.NANOSECONDS)) {
        TaskRunner.INSTANCE.withLock {
          TaskRunner.INSTANCE.cancelAll()
        }
        fail<Unit>("Queue still active after 1000 ms")
      }
    }
  }

         * @return The response.
         */
        public RESPONSE getResponse(final long time, final TimeUnit unit) {
            try {
                final boolean isTimeout = !latch.await(time, unit);
                if (isTimeout) {
                    throw new SuggesterException("Request timeout. time:" + time + " unit:" + unit.name());
                }
                if (error != null) {

def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>অথবা ব্যবহার করুন <code>async def</code>...</summary>

যদি আপনার কোড `async` / `await`, ব্যবহার করে তাহলে `async def` ব্যবহার করুন:

```Python hl_lines="9  14"
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def read_root():

def read_item(item_id: int, q: Union[str, None] = None):
    return {"item_id": item_id, "q": q}
```

<details markdown="1">
<summary>Vagy használd az <code>async def</code>-et...</summary>

Ha a kódod `async` / `await`-et, használ `async def`:

```Python hl_lines="9  14"
from typing import Union

from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def read_root():

   */

  @GuardedBy("lock")
  private void await(Guard guard, boolean signalBeforeWaiting) throws InterruptedException {
    if (signalBeforeWaiting) {
      signalNextWaiter();
    }
    beginWaitingFor(guard);
    try {
      do {
        guard.condition.await();
      } while (!guard.isSatisfied());
    } finally {
      endWaitingFor(guard);
    }