You will learn more about adding extra information later in the docs, when learning to declare examples.

/// warning

Extra keys passed to `Field` will also be present in the resulting OpenAPI schema for your application.
As these keys may not necessarily be part of the OpenAPI specification, some OpenAPI tools, for example [the OpenAPI validator](https://validator.swagger.io/), may not work with your generated schema.

///

You just pass it to `Depends` and **FastAPI** knows how to do the rest.

///

## Share `Annotated` dependencies

In the examples above, you see that there's a tiny bit of **code duplication**.

When you need to use the `common_parameters()` dependency, you have to write the whole parameter with the type annotation and `Depends()`:

```Python

{* ../../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.

 *
 * All callback methods (will) follow beforeXXX/afterXXX naming pattern to
 * indicate at what lifecycle point it is being called.
 *
 * @see <a href="https://maven.apache.org/examples/maven-3-lifecycle-extensions.html">example</a>
 * @see <a href="https://issues.apache.org/jira/browse/MNG-4224">MNG-4224</a>
 * @since 3.0-alpha-3
 */
public abstract class AbstractMavenLifecycleParticipant {

    /**

## Integrated middlewares

**FastAPI** includes several middlewares for common use cases, we'll see next how to use them.

/// note | "Technical Details"

For the next examples, you could also use `from starlette.middleware.something import SomethingMiddleware`.

     */
    List<String> findVersions(Artifact artifact);

    /**
     * Indicates whether this repository is backed by actual projects. For instance, the build reactor or IDE workspace
     * are examples of such repositories.
     *
     * @return {@code true} if the repository is backed by actual projects, {@code false} otherwise.
     * @since 3.0-beta-1
     */
    boolean isProjectAware();

    /**

Each "scope" is just a string (without spaces).

They are normally used to declare specific security permissions, for example:

* `users:read` or `users:write` are common examples.
* `instagram_basic` is used by Facebook / Instagram.
* `https://www.googleapis.com/auth/drive` is used by Google.

/// info

In all the docs there are examples compatible with each version of Python (when there's a difference).

For example "**Python 3.6+**" means it's compatible with Python 3.6 or above (including 3.7, 3.8, 3.9, 3.10, etc). And "**Python 3.9+**" means it's compatible with Python 3.9 or above (including 3.10, etc).

## Introduction

[Istio](https://istio.io/latest/docs/concepts/what-is-istio/) is an open platform for providing a uniform way to [integrate
microservices](https://istio.io/latest/docs/examples/microservices-istio/), manage [traffic flow](https://istio.io/latest/docs/concepts/traffic-management/) across microservices, enforce policies
and aggregate telemetry data. Istio's control plane provides an abstraction

of the conventional `istio-injected: true`. The name of the environment is defined as the namespace
where the corresponding control plane components (config, discovery, auto-injection) are running.
In the examples below, by default this is the `istio-control` namespace. Pod annotations can also
be used to select a different 'environment'.

## Installing