first_child.read_source(config=config)
                    new_title = first_child.title or new_title
            # Creating a new section makes it render it collapsed by default
            # no idea why, so, let's just modify the existing one
            # new_section = Section(title=new_title, children=new_children)
            item.title = new_title
            item.children = new_children

    If you don't know, you will learn what a "password hash" is in the [security chapters](security/simple-oauth2.md#password-hashing){.internal-link target=_blank}.

## Multiple models

Here's a general idea of how the models could look like with their password fields and the places where they are used:

=== "Python 3.10+"

    ```Python hl_lines="7  9  14  20  22  27-28  31-33  38-39"

Other common terms for this same idea of "dependency injection" are:

* resources
* providers
* services
* injectables
* components

## **FastAPI** plug-ins

Just remember, the most important point is: try to be kind. People come with their frustrations and in many cases don't ask in the best way, but try as best as you can to be kind. 🤗

The idea is for the **FastAPI** community to be kind and welcoming. At the same time, don't accept bullying or disrespectful behavior towards others. We have to take care of each other.

---

```Python hl_lines="2-5  15  21"
{!../../../docs_src/handling_errors/tutorial006.py!}
```

Special thanks to [@nzig](https://github.com/nzig) for the core implementation and to [@adriangb](https://github.com/adriangb) for the inspiration and idea with [Xpresso](https://github.com/adriangb/xpresso)! 🚀

### Features

### Using context managers in dependencies with `yield`

!!! warning
    This is, more or less, an "advanced" idea.

    If you are just starting with **FastAPI** you might want to skip it for now.

### Concurrency and Burgers

This idea of **asynchronous** code described above is also sometimes called **"concurrency"**. It is different from **"parallelism"**.

**Concurrency** and **parallelism** both relate to "different things happening more or less at the same time".

    * Automatic client code generation systems, for many languages.
* Provide 2 interactive documentation web interfaces directly.

---

We just scratched the surface, but you already get the idea of how it all works.

Try changing the line with:

```Python
    return {"item_name": item.name, "item_id": item_id}
```

...from:

```Python
        ... "item_name": item.name ...
```

    * Automatic client code generation systems, for many languages.
* Provide 2 interactive documentation web interfaces directly.

---

We just scratched the surface, but you already get the idea of how it all works.

Try changing the line with:

```Python
    return {"item_name": item.name, "item_id": item_id}
```

...from:

```Python
        ... "item_name": item.name ...
```