/**
     * Invoked just before session is created with a mutable map that carries collected user properties so far.
     *
     * @param userProperties The mutable user properties, never {@code null}.
     * @see #contribute(ProtoSession)
     */
    default void contribute(Map<String, String> userProperties) {}

    /**

## Why is MinIO cloud-native?

// that pass integers back and forth.  No actual
// concurrency, just threads and synchronization
// and foreign code on multiple pthreads.

package main

import (
	big "."
	"runtime"
)

func fibber(c chan *big.Int, out chan string, n int64) {
	// Keep the fibbers in dedicated operating system
	// threads, so that this program tests coordination
	// between pthreads and not just goroutines.
	runtime.LockOSThread()

For that, use the standard Python `typing.List` (or just `list` in Python 3.9 and above):

{* ../../docs_src/extra_models/tutorial004_py39.py hl[18] *}

## Response with arbitrary `dict` { #response-with-arbitrary-dict }

You can also declare a response using a plain arbitrary `dict`, declaring just the type of the keys and values, without using a Pydantic model.

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 OAuth2 a "scope" is just a string that declares a specific permission required.

@Experimental
@Consumer
@Named
public interface ModelTransformer extends SpiService {

    /**
     * Apply a transformation on the file model.
     *
     * This method will be called on each file model being loaded,
     * just before validation.
     *
     * @param model the input model
     * @return the transformed model, or the input model if no transformation is needed
     * @throws ModelTransformerException
     */
    @Nonnull

Si vous ne voulez pas leur donner de valeur par défaut mais juste les rendre optionnels, utilisez `None` comme valeur par défaut.

Mais si vous voulez rendre un paramètre de requête obligatoire, vous pouvez juste ne pas y affecter de valeur par défaut :

{* ../../docs_src/query_params/tutorial005.py hl[6:7] *}

But this way we can focus on how the **Dependency Injection** system works.

### Create a dependency, or "dependable" { #create-a-dependency-or-dependable }

Let's first focus on the dependency.

It is just a function that can take all the same parameters that a *path operation function* can take:

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[8:9] *}

That's it.

**2 lines**.

```Python hl_lines="2"
@app.get('/')
def results():
    results = some_library()
    return results
```

---

If your application (somehow) doesn't have to communicate with anything else and wait for it to respond, use `async def`, even if you don't need to use `await` inside.

---

If you just don't know, use normal `def`.

---

That doesn't add any extra security to your API, the *path operations* will still be available where they are.

If there's a security flaw in your code, it will still exist.