**"Dependency Injection"** means, in programming, that there is a way for your code (in this case, your *path operation functions*) to declare things that it requires to work and use: "dependencies".

And then, that system (in this case **FastAPI**) will take care of doing whatever is needed to provide your code with those needed dependencies ("inject" the dependencies).

This is very useful when you need to:

Such a set typically includes many root certificates from well-known certificate authorities like
Entrust and Verisign.

This is the behavior you'll get with your OkHttpClient if you don't specifically configure
`HandshakeCertificates`. Or you can do it explicitly with `addPlatformTrustedCertificates()`:

```java

* `allow_origin_regex` - Une chaîne regex pour faire correspondre les origines autorisées à effectuer des requêtes cross-origin. Par ex. `'https://.*\.example\.org'`.
* `allow_methods` - Une liste de méthodes HTTP qui doivent être autorisées pour les requêtes cross-origin. Par défaut `['GET']`. Vous pouvez utiliser `['*']` pour autoriser toutes les méthodes standard.

      // We check the state after adding the listener as a way to ensure that our listener was added
      // to a NEW service.
      checkArgument(service.state() == NEW, "Can only manage NEW services, %s", service);
    }
    // We have installed all of our listeners and after this point any state transition should be
    // correct.
    this.state.markReady();
  }

  /**

For details on best practices with 2.0, see
[the Effective 2.0 guide](https://www.tensorflow.org/beta/guide/effective_tf2)

For information on upgrading your existing TensorFlow 1.x models, please refer
to our
[Upgrade](https://medium.com/tensorflow/upgrading-your-code-to-tensorflow-2-0-f72c3a4d83b5)
and [Migration](https://www.tensorflow.org/beta/guide/migration_guide) guides.
We have also released a collection of

# Request Body { #request-body }

When you need to send data from a client (let's say, a browser) to your API, you send it as a **request body**.

A **request** body is data sent by the client to your API. A **response** body is the data your API sends to the client.

vous renvoyez un type différent du modèle de réponse, pour qu'il soit utilisé par l'éditeur et des outils comme mypy. Et vous pouvez toujours laisser FastAPI faire la validation des données, la documentation, etc. avec `response_model`.

Vous pouvez également utiliser `response_model=None` pour désactiver la création d’un modèle de réponse pour ce *chemin d'accès* ; vous pourriez en avoir besoin si vous ajoutez des annotations de type pour des choses qui ne sont pas des champs valides Pydantic,...

```java
okHttpClient.setSslSocketFactory(HttpsURLConnection.getDefaultSSLSocketFactory());
```

A simpler solution is to avoid the shared default SSL socket factory. Instead, if you
need to customize SSL, do so for your specific OkHttpClient instance only.

##### Synthetic headers have changed

Previously OkHttp added a synthetic response header, `OkHttp-Selected-Transport`. It

 * the behavior of {@link #addAll}, which can lead to unexpected behavior. In this case, you should
 * override {@code addAll} as well, either providing your own implementation, or delegating to the
 * provided {@code standardAddAll} method.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code

 * the behavior of {@link #addAll}, which can lead to unexpected behavior. In this case, you should
 * override {@code addAll} as well, either providing your own implementation, or delegating to the
 * provided {@code standardAddAll} method.
 *
 * <p><b>{@code default} method warning:</b> This class does <i>not</i> forward calls to {@code