### 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

### Response Elements

XML response for this API is similar to [AWS STS AssumeRole](https://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRole.html#API_AssumeRole_ResponseElements)

### Errors

XML error response for this API is similar to [AWS STS AssumeRole](https://docs.aws.amazon.com/STS/latest/APIReference/API_AssumeRole.html#API_AssumeRole_Errors)

## Sample `POST` Request

```

    }

    @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

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")

  // A consequence of these requirements is that the delegate futures cannot be stored in
  // final fields.
  //
  // For simplicity the rest of this description will discuss Futures.catching since it is the
  // simplest instance, though very similar descriptions apply to many other classes in this file.
  //
  // In the constructor of AbstractCatchingFuture, the delegate future is assigned to a field

{* ../../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.

 - [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)

![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>.

	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.