// Test implementation
    }
    
    public boolean waitForNotification(long timeoutMs) throws InterruptedException {
        return latch.await(timeoutMs, TimeUnit.MILLISECONDS);
    }
    
    public boolean isNotificationReceived() {
        return notificationReceived;
    }
}
```

## 8. Error Handling and Reliability

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

<details markdown="1">
<summary>또는 <code>async def</code> 사용하기...</summary>

여러분의 코드가 `async` / `await`을 사용한다면, `async def`를 사용하십시오:

```Python hl_lines="7  12"
from fastapi import FastAPI

app = FastAPI()


@app.get("/")
async def read_root():
    return {"Hello": "World"}

    assertThat(e.getCause()).isEqualTo(exception);
  }

  private static void awaitUnchecked(CyclicBarrier barrier) {
    try {
      barrier.await();
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

  private void checkStackTrace(ExecutionException e) {
    // Our call site for get() should be in the trace.

		if zinfo == nil {
			serverPools[i] = poolAvailableSpace{Index: i}
			continue
		}
		var available uint64
		if !isMinioMetaBucketName(bucket) {
			if avail, err := hasSpaceFor(zinfo, size); err != nil || !avail {
				serverPools[i] = poolAvailableSpace{Index: i}
				continue
			}
		}
		var maxUsedPct int
		for _, disk := range zinfo {
			if disk == nil || disk.Total == 0 {
				continue

          call: Call,
          response: Response,
        ) {
          response.close()
          completionLatch.countDown()
        }
      }
    call.enqueue(callback)
    completionLatch.await()
    assertThat(eventRecorder.recordedEventTypes()).containsExactly(
      CallStart::class,
      ProxySelectStart::class,
      ProxySelectEnd::class,
      DnsStart::class,
      DnsEnd::class,

    assertThat(e.getCause()).isEqualTo(exception);
  }

  private static void awaitUnchecked(CyclicBarrier barrier) {
    try {
      barrier.await();
    } catch (Exception e) {
      throw new RuntimeException(e);
    }
  }

  private void checkStackTrace(ExecutionException e) {
    // Our call site for get() should be in the trace.

                final CommonServerMessageBlockRequest next = chain.getNext();
                if (log.isTraceEnabled()) {
                    log.trace(String.format("%s costs %d avail %d (%s)", chain.getClass().getName(), cost, this.credits.availablePermits(),
                            this.name));
                }

* Fix typos in Async docs. PR [#1423](https://github.com/tiangolo/fastapi/pull/1423).

## 0.54.2 (2020-05-16)

* Add translation to Spanish for [Concurrency and async / await - Concurrencia y async / await](https://fastapi.tiangolo.com/es/async/). PR [#1290](https://github.com/tiangolo/fastapi/pull/1290) by [@alvaropernas](https://github.com/alvaropernas).