cache.getUnchecked(1);
      cache.getUnchecked(2);

      Set<Object> keys = cache.asMap().keySet();
      // We don't know whether these are still in the cache, so we can't assert on the return
      // values of these removes, but the cache should be empty after the removes, regardless.
      keys.remove(1);
      keys.remove(2);
      assertThat(keys.remove(null)).isFalse();

      cache.getUnchecked(1);
      cache.getUnchecked(2);

      Set<Object> keys = cache.asMap().keySet();
      // We don't know whether these are still in the cache, so we can't assert on the return
      // values of these removes, but the cache should be empty after the removes, regardless.
      keys.remove(1);
      keys.remove(2);
      assertThat(keys.remove(null)).isFalse();

        synchronized (queue) {
          workerRunningState = IDLE;
        }
        throw e;
        // The execution of a task has ended abnormally.
        // We could have tasks left in the queue, so should perhaps try to restart a worker,
        // but then the Error will get delayed if we are using a direct (same thread) executor.
      }
    }

    /**

**FastAPI** knows what to do in each case and how to reuse the same object, so that all the background tasks are merged together and are run in the background afterwards:


{* ../../docs_src/background_tasks/tutorial002_an_py310.py hl[13,15,22,25] *}

 * {@code com.google.common.util.concurrent}) in degenerate class loaders which make certain
 * platform classes unavailable. Then we construct a test suite so we can run the normal
 * AbstractFutureTest test methods in these degenerate classloaders.
 */

@NullUnmarked
public class AbstractFutureFallbackAtomicHelperTest extends TestCase {

     <span style="background-color:#007166"><font color="#D3D7CF"> INFO </font></span>  Application startup complete.
```

</div>

In der Konsolenausgabe sollte es eine Zeile geben, die ungefähr so aussieht:

```hl_lines="4"
INFO:     Uvicorn running on http://127.0.0.1:8000 (Press CTRL+C to quit)
```

Diese Zeile zeigt die URL, unter der Ihre App auf Ihrem lokalen Computer bereitgestellt wird.

Here, if you request `/unicorns/yolo`, the *path operation* will `raise` a `UnicornException`.

But it will be handled by the `unicorn_exception_handler`.

So, you will receive a clean error, with an HTTP status code of `418` and a JSON content of:

```JSON
{"message": "Oops! yolo did something. There goes a rainbow..."}
```

/// note | Technical Details

                "description": "Operations with users. The **login** logic is also here.",
            },
            {
                "name": "items",
                "description": "Manage items. So _fancy_ they have their own docs.",
                "externalDocs": {
                    "description": "Items external docs",
                    "url": "https://fastapi.tiangolo.com/",
                },
            },

   * of the function in [7.0, 10.0] is equivalent to the sum of the integrals of [7.0, 8.0], [8.0,
   * 9.0], [9.0, 10.0] (and so on), no matter what the function is. This guarantees that we handle
   * correctly requests of varying weight (permits), /no matter/ what the actual function is - so we
   * can tweak the latter freely. (The only requirement, obviously, is that we can compute its
   * integrals).
   *

Lassen Sie uns nun etwas zurückgehen und verstehen, was das alles ist.

Der `password`-„Flow“ ist eine der in OAuth2 definierten Wege („Flows“) zur Handhabung von Sicherheit und Authentifizierung.

OAuth2 wurde so konzipiert, dass das Backend oder die API unabhängig vom Server sein kann, der den Benutzer authentifiziert.

In diesem Fall handhabt jedoch dieselbe **FastAPI**-Anwendung sowohl die API als auch die Authentifizierung.