...and have the code for the tests just like before.

## Testing: extended example

Now let's extend this example and add more details to see how to test different parts.

### Extended **FastAPI** app file

Let's continue with the same file structure as before:

```
.
├── app
│   ├── __init__.py
│   ├── main.py
│   └── test_main.py
```

That's why in this example we have to declare it in the `response_model` parameter.

...but continue reading below to see how to overcome that.

## Return Type and Data Filtering

Let's continue from the previous example. We wanted to **annotate the function with one type** but return something that includes **more data**.

<img class="shadow" src="/img/deployment/concepts/image01.png">

---

Now that we know the difference between the terms **process** and **program**, let's continue talking about deployments.

## Running on Startup

Ao invés disso, sendo um sistema "assíncrono", uma vez finalizada, a tarefa pode esperar um pouco (alguns microssegundos) para que o computador / programa finalize o que quer que esteja fazendo,e então volte para pegar o resultado e continue trabalhando com ele.

```Python hl_lines="3" title="app/routers/items.py"
{!../../../docs_src/bigger_applications/app/routers/items.py!}
```

#### How relative imports work

!!! tip
    If you know perfectly how imports work, continue to the next section below.

A single dot `.`, like in:

```Python
from .dependencies import get_token_header
```

would mean:

Some of them also ✨ [**sponsor FastAPI**](../help-fastapi.md#sponsor-the-author){.internal-link target=_blank} ✨, this ensures the continued and healthy **development** of FastAPI and its **ecosystem**.

        at_least_one_scalar_sequence = False
        for arg in get_args(annotation):
            if field_annotation_is_scalar_sequence(arg):
                at_least_one_scalar_sequence = True
                continue
            elif not field_annotation_is_scalar(arg):
                return False
        return at_least_one_scalar_sequence
    return field_annotation_is_sequence(annotation) and all(

Instead of that, by being an "asynchronous" system, once finished, the task can wait in line a little bit (some microseconds) for the computer / program to finish whatever it went to do, and then come back to take the results and continue working with them.

	Usar uma URL relativa é importante para garantir que sua aplicação continue funcionando, mesmo em um uso avançado tipo [Atrás de um Proxy](../../advanced/behind-a-proxy.md){.internal-link target=_blank}.

    parameters = []
    for param in all_route_params:
        field_info = param.field_info
        field_info = cast(Param, field_info)
        if not field_info.include_in_schema:
            continue
        param_schema = get_schema_from_model_field(
            field=param,
            schema_generator=schema_generator,
            model_name_map=model_name_map,
            field_mapping=field_mapping,