## Current Behavior
<!--- If describing a bug, tell us what happens instead of the expected behavior -->
<!--- If suggesting a change/improvement, explain the difference from current behavior -->

## Possible Solution
<!--- Not obligatory, but suggest a fix/reason for the bug, -->
<!--- or ideas how to implement the addition or change -->

## Steps to Reproduce (for bugs)

////

//// tab | Python 3.8+

```Python
{!> ../../docs_src/security/tutorial001_an.py!}
```

////

//// tab | Python 3.8+ non-Annotated

/// tip

Prefer to use the `Annotated` version if possible.

///

```Python
{!> ../../docs_src/security/tutorial001.py!}
```

////

## Run it

/// info

stated above is already equivalent to code execution. In any case, the
recommendation is not to serve models using Eager mode since it also has
performance limitations.

## Multi-Tenant environments

It is possible to run multiple TensorFlow models in parallel. For example,
`ModelServer` collates all computation graphs exposed to it (from multiple
`SavedModel`) and executes them in parallel on available executors. Running

		Method: http.MethodPost,
		URL:    u,
	}
	if !guessIsRPCReq(r) {
		t.Fatal("Test shouldn't fail for a possible net/rpc request.")
	}
	r = &http.Request{
		Proto:  "HTTP/1.1",
		Method: http.MethodGet,
		URL:    u,
	}
	if !guessIsRPCReq(r) {
		t.Fatal("Test shouldn't fail for a possible net/rpc request.")
	}
	r = &http.Request{
		Proto:  "HTTP/1.1",
		Method: http.MethodGet,

But at some point, there was no other option than creating something that provided all these features, taking the best ideas from previous tools, and combining them in the best way possible, using language features that weren't even available before (Python 3.6+ type hints).

</blockquote>

## Investigation

Dans les sections suivantes, vous verrez des options, configurations et fonctionnalités supplémentaires.

/// note | "Remarque"

Les sections de ce chapitre ne sont **pas nécessairement "avancées"**.

Et il est possible que pour votre cas d'utilisation, la solution se trouve dans l'un d'entre eux.

///

## Lisez d'abord le didacticiel

the HTTP client and the HTTP server.
It is also possible to set the default `GODEBUG` for a given program
(discussed below).

When preparing any change that is permitted by Go 1 compatibility
but may nonetheless break some existing programs,
we first engineer the change to keep as many existing programs working as possible.
For the remaining programs,
we define a new GODEBUG setting that

 * This information include the dependency type (main classes, test classes, <i>etc.</i>),
 * a scope (compile-time, run-time <i>etc.</i>), an obligation (whether the dependency
 * is optional or mandatory), and possible exclusions for transitive dependencies.
 * The {@linkplain #getVersionConstraint() version} and the {@linkplain #getOptional() obligation}
 * may not be defined precisely.
 *
 * @since 4.0.0
 */
@Experimental

In Python 3.6 and above (including Python 3.10) you can use the `Union` type from `typing` and put inside the square brackets the possible types to accept.

In Python 3.10 there's also a **new syntax** where you can put the possible types separated by a <abbr title='also called "bitwise or operator", but that meaning is not relevant here'>vertical bar (`|`)</abbr>.

//// tab | Python 3.10+

By only using `BackgroundTasks` (and not `BackgroundTask`), it's then possible to use it as a *path operation function* parameter and have **FastAPI** handle the rest for you, just like when using the `Request` object directly.

It's still possible to use `BackgroundTask` alone in FastAPI, but you have to create the object in your code and return a Starlette `Response` including it.