opts.SetEvalMetadataFn(func(oi *ObjectInfo, gerr error) (dsc ReplicateDecision, err error) {
		if replica { // no need to check replication on receiver
			return dsc, nil
		}
		dsc = checkReplicateDelete(ctx, bucket, ObjectToDelete{
			ObjectV: ObjectV{
				ObjectName: object,
				VersionID:  opts.VersionID,
			},
		}, *oi, opts, gerr)

Let's imagine that you have a database `fake_db` that only receives JSON compatible data.

For example, it doesn't receive `datetime` objects, as those are not compatible with JSON.

So, a `datetime` object would have to be converted to a `str` containing the data in <a href="https://en.wikipedia.org/wiki/ISO_8601" class="external-link" target="_blank">ISO format</a>.

If a client tries to send some **extra cookies**, they will receive an **error** response.

Poor cookie banners with all their effort to get your consent for the <abbr title="This is another joke. Don't pay attention to me. Have some coffee for your cookie. ☕">API to reject it</abbr>. 🍪

///

The `status_code` parameter receives a number with the HTTP status code.

/// info

`status_code` can alternatively also receive an `IntEnum`, such as Python's <a href="https://docs.python.org/3/library/http.html#http.HTTPStatus" class="external-link" target="_blank">`http.HTTPStatus`</a>.

///

The `RequestValidationError` contains the `body` it received with invalid data.

You could use it while developing your app to log the body and debug it, return it to the user, etc.

{* ../../docs_src/handling_errors/tutorial005.py hl[14] *}

Now try sending an invalid item like:

```JSON
{
  "title": "towel",
  "size": "XL"
}
```

We are still using the same `OAuth2PasswordRequestForm`. It includes a property `scopes` with a `list` of `str`, with each scope it received in the request.

And we return the scopes as part of the JWT token.

/// danger

For simplicity, here we are just adding the scopes received directly to the token.

```Python
from fastapi import FastAPI
from unicorn import UnicornMiddleware

app = FastAPI()

app.add_middleware(UnicornMiddleware, some_config="rainbow")
```

`app.add_middleware()` receives a middleware class as the first argument and any additional arguments to be passed to the middleware.

## Integrated middlewares { #integrated-middlewares }

    * This way you can update only the values actually set by the user, instead of overriding values already stored with default values in your model.
* Create a copy of the stored model, updating its attributes with the received partial updates (using the `update` parameter).
* Convert the copied model to something that can be stored in your DB (for example, using the `jsonable_encoder`).

## Query parameter list / multiple values { #query-parameter-list-multiple-values }

When you define a query parameter explicitly with `Query` you can also declare it to receive a list of values, or said in another way, to receive multiple values.

For example, to declare a query parameter `q` that can appear multiple times in the URL, you can write:

Notice that even though the `item` was declared the same way as before, it is now expected to be inside of the body with a key `item`.

///

**FastAPI** will do the automatic conversion from the request, so that the parameter `item` receives its specific content and the same for `user`.

It will perform the validation of the compound data, and will document it like that for the OpenAPI schema and automatic docs.