First, we create a `GzipRequest` class, which will overwrite the `Request.body()` method to decompress the body in the presence of an appropriate header.

If there's no `gzip` in the header, it will not try to decompress the body.

That way, the same route class can handle gzip compressed or uncompressed requests.

```Python hl_lines="8-15"

That configuration would change the syntax highlighting color theme:

<img src="/img/tutorial/extending-openapi/image04.png">

## Change Default Swagger UI Parameters

FastAPI includes some default configuration parameters appropriate for most of the use cases.

It includes these default configurations:

```Python
{!../../../fastapi/openapi/docs.py[ln:7-23]!}
```

In this case the middleware will intercept the incoming request and respond with appropriate CORS headers, and either a `200` or `400` response for informational purposes.

### Simple requests

Any request with an `Origin` header. In this case the middleware will pass the request through as normal, but will include appropriate CORS headers on the response.

## More info

    * HTTP Basic authentication.
    * HTTP Digest, etc.
* `oauth2`: all the OAuth2 ways to handle security (called "flows").
    * Several of these flows are appropriate for building an OAuth 2.0 authentication provider (like Google, Facebook, Twitter, GitHub, etc):
        * `implicit`
        * `clientCredentials`
        * `authorizationCode`