for (Integer node : network.nodes()) {
                    Set<Integer> unused = network.successors(node);
                  }
                  /*
                   * Also look up an earlier node so that, if the graph is using MapRetrievalCache,
                   * we read one of the fields declared in that class.
                   */

{!../../docs_src/handling_errors/tutorial003.py!}
```

Wenn Sie nun `/unicorns/yolo` anfragen, `raise`d die *Pfadoperation* eine `UnicornException`.

Aber diese wird von `unicorn_exception_handler` gehandhabt.

Sie erhalten also einen sauberen Error mit einem Statuscode `418` und dem JSON-Inhalt:

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

/// note | "Technische Details"

`UploadFile` hat die folgenden `async`hronen Methoden. Sie alle rufen die entsprechenden Methoden des darunterliegenden Datei-Objekts auf (wobei intern `SpooledTemporaryFile` verwendet wird).

* `write(daten)`: Schreibt `daten` (`str` oder `bytes`) in die Datei.

Então, no **FastAPI**, você pode utilizar uma classe Python como uma dependência.

O que o FastAPI realmente verifica, é se a dependência é algo chamável (função, classe, ou outra coisa) e os parâmetros que foram definidos.

{% endfor %}

</div>
{% endif %}

### FastAPI Experts - All Time

Here are the all time **FastAPI Experts**. 🤓🤯

These are the users that have [helped others the most with questions in GitHub](help-fastapi.md#help-others-with-questions-in-github){.internal-link target=_blank} through *all time*. 🧙

{% if people %}
<div class="user-list user-list-center">

That also applies to callables with no parameters at all. The same as it would be for *path operation functions* with no parameters.

Then, we can change the dependency "dependable" `common_parameters` from above to the class `CommonQueryParams`:

## Meningen

"_[...] Ik gebruik **FastAPI** heel vaak tegenwoordig. [...] Ik ben van plan om het te gebruiken voor alle **ML-services van mijn team bij Microsoft**. Sommige van deze worden geïntegreerd in het kernproduct van **Windows** en sommige **Office**-producten._"

   * is permitted and similarly for decrease/remove(). We assume that a
   * setCount() no-op is permitted if either add() or remove() is permitted,
   * though we also allow it to "succeed" if neither is permitted.
   */

  private void assertSetCount(E element, int count) {
    setCountCheckReturnValue(element, count);

    assertEquals(

    assertEquals("null [5, 6]", Strings.lenientFormat(null, 5, 6));
    assertEquals("null", Strings.lenientFormat("%s", (Object) null));
  }

  @J2ktIncompatible // TODO(b/319404022): Allow passing null array as varargs
  public void testLenientFormat_nullArrayVarargs() {
    assertEquals("(Object[])null", Strings.lenientFormat("%s", (Object[]) null));
  }

    return oldCount;
  }

  private static int getAndSet(@CheckForNull Count i, int count) {
    if (i == null) {
      return 0;
    }

    return i.getAndSet(count);
  }

  // Don't allow default serialization.
  @GwtIncompatible // java.io.ObjectStreamException
  @J2ktIncompatible
  private void readObjectNoData() throws ObjectStreamException {
    throw new InvalidObjectException("Stream data required");