* Property to use to retrieve a value. Can come from <code>-D</code> execution, setting properties or pom
     * properties.
     * @return property name
     */
    @Nonnull
    String property() default "";

    /**
     * parameter default value, may contain <code>${...}</code> expressions which will be interpreted at
     * inject time: see

///

## Add custom headers { #add-custom-headers }

There are some situations in where it's useful to be able to add custom headers to the HTTP error. For example, for some types of security.

You probably won't need to use it directly in your code.

But in case you needed it for an advanced scenario, you can add custom headers:

{* ../../docs_src/handling_errors/tutorial002_py39.py hl[14] *}

You could also use `from starlette.responses import JSONResponse`.

**FastAPI** provides the same `starlette.responses` as `fastapi.responses` just as a convenience for you, the developer. But most of the available responses come directly from Starlette.

///

## Returning a custom `Response` { #returning-a-custom-response }

[codeofconduct_at]: mailto:codeofconduct@squareup.com
[twitter_coc]: https://github.com/twitter/code-of-conduct/blob/master/code-of-conduct.md
[ubuntu_coc]: https://ubuntu.com/community/code-of-conduct
[gdc_coc]: https://www.gdconf.com/code-of-conduct

Asynchronous code just means that the language 💬 has a way to tell the computer / program 🤖 that at some point in the code, it 🤖 will have to wait for *something else* to finish somewhere else. Let's say that *something else* is called "slow-file" 📝.

So, during that time, the computer can go and do some other work, while "slow-file" 📝 finishes.

        All that, on top of all the incredible help provided by a bunch of community members, the [FastAPI Experts](https://fastapi.tiangolo.com/fastapi-people/#experts), that give a lot of their time to come here and help others.

        That's a lot of work they are doing, but if more FastAPI users came to help others like them just a little bit more, it would be much less effort for them (and you and me 😅).

for it.

If we decide to pursue a feature request, it will go through a thorough process
of API design and review. Any code should come after this.

[APIs]: https://en.wikipedia.org/wiki/API
[issue]: https://github.com/google/guava/issues

Pull requests
-------------

Unless the change is a trivial fix such as for a typo, it's generally best to

It is also built to work as a future reference so you can come back and see exactly what you need.

## Run the code { #run-the-code }

All the code blocks can be copied and used directly (they are actually tested Python files).

To run any of the examples, copy the code to a file `main.py`, and start `fastapi dev` with:

<div class="termy">

```console

        if (Artifact.SCOPE_PROVIDED.equals(inheritedScope)) {
            desiredScope = Artifact.SCOPE_PROVIDED;
        }

        if (Artifact.SCOPE_SYSTEM.equals(scope)) {
            // system scopes come through unchanged...
            desiredScope = Artifact.SCOPE_SYSTEM;
        }

        ArtifactHandler handler = artifactHandlerManager.getArtifactHandler(type);

        return new DefaultArtifact(

     * @return This request, never {@code null}.
     */
    ProjectBuildingRequest setUserProperties(Properties userProperties);

    /**
     * Gets the user properties to use for interpolation and profile activation. The user properties have been
     * configured directly by the user on his discretion, e.g. via the {@code -Dkey=value} parameter on the command
     * line.
     *