### Use the `app.dependency_overrides` attribute { #use-the-app-dependency-overrides-attribute }

For these cases, your **FastAPI** application has an attribute `app.dependency_overrides`, it is a simple `dict`.

To override a dependency for testing, you put as a key the original dependency (a function), and as the value, your dependency override (another function).

    private ReserializedSetGenerator(OneSizeTestContainerGenerator<Collection<E>, E> gen) {
      this.gen = gen;
    }

    @Override
    public SampleElements<E> samples() {
      return gen.samples();
    }

    @Override
    public Set<E> create(Object... elements) {
      return (Set<E>) SerializableTester.reserialize(gen.create(elements));
    }

    @Override

    }

    @Test
    @DisplayName("Constructor acquires tree connection; getConfig/isConnected delegate")
    void constructorAndSimpleDelegations() {
        // Ensures constructor acquires tree connection and simple delegate methods forward correctly
        // Verify constructor invoked acquire once
        verify(treeConnection, times(1)).acquire();

        // getConfig delegates

 * to implement the related methods as well. Finally, two collection views are provided: {@link
 * #elementSet} contains the distinct elements of the multiset "with duplicates collapsed", and
 * {@link #entrySet} is similar but contains {@link Entry Multiset.Entry} instances, each providing
 * both a distinct element and the count of that element.
 *
 * <p>In addition to these required methods, implementations of {@code Multiset} are expected to

import org.junit.jupiter.api.Test;

/**
 * Tests for SpnegoConstants interface.
 * Verifies constant values, modifiers, types, and structural properties.
 */
class SpnegoConstantsTest {

    // Simple OID format: numbers separated by dots (at least one dot)
    private static final Pattern OID_PATTERN = Pattern.compile("\\d+(?:\\.\\d+)+");

    @Test
    @DisplayName("Constant values match expected OIDs")

{* ../../docs_src/dependencies/tutorial011_an_py39.py hl[22] *}

/// tip

All this might seem contrived. And it might not be very clear how is it useful yet.

These examples are intentionally simple, but show how it all works.

In the chapters about security, there are utility functions that are implemented in this same way.

If you understood all this, you already know how those utility tools for security work underneath.

Elle peut être une fonction asynchrone (`async def`) ou une fonction normale (`def`), **FastAPI** saura la gérer correctement.

Dans cet exemple, la fonction de tâche écrira dans un fichier (afin de simuler un envoi d'email).

L'opération d'écriture n'utilisant ni `async` ni `await`, on définit la fonction avec un `def` normal.

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

## Ajouter une tâche d'arrière-plan

![Swagger UI](https://fastapi.tiangolo.com/img/index/index-01-swagger-ui-simple.png)

### Alternative API-Dokumentation

Gehen Sie nun auf <a href="http://127.0.0.1:8000/redoc" class="external-link" target="_blank">http://127.0.0.1:8000/redoc</a>.

 - [Salesforce](https://github.com/codelibs/fess-ds-salesforce)
 - [SharePoint](https://github.com/codelibs/fess-ds-sharepoint)
 - [Slack](https://github.com/codelibs/fess-ds-slack)

## 테마

 - [Simple](https://github.com/codelibs/fess-theme-simple)
 - [Classic](https://github.com/codelibs/fess-theme-classic)

## 인게스트

 - [Logger](https://github.com/codelibs/fess-ingest-logger)
 - [NDJSON](https://github.com/codelibs/fess-ingest-ndjson)

	req, err := newTestRequest(method, urlStr, contentLength, body)
	if err != nil {
		t.Fatalf("Unable to initialize new http request %s", err)
	}
	return req
}

// This is similar to mustNewRequest but additionally the request
// is signed with AWS Signature V4, fails if not able to do so.