# Classes as Dependencies { #classes-as-dependencies }

Before diving deeper into the **Dependency Injection** system, let's upgrade the previous example.

## A `dict` from the previous example { #a-dict-from-the-previous-example }

In the previous example, we were returning a `dict` from our dependency ("dependable"):

{* ../../docs_src/dependencies/tutorial001_an_py310.py hl[9] *}

<div class="termy">

```console
$ python -m pip install --upgrade pip

---> 100%
```

</div>

/// tip | Dica

Às vezes, você pode receber um erro **`No module named pip`** ao tentar atualizar o pip.

Se isso acontecer, instale e atualize o pip usando o comando abaixo:

<div class="termy">

```console
$ python -m ensurepip --upgrade

---> 100%
```

</div>

<div class="termy">

```console
$ python -m pip install --upgrade pip

---> 100%
```

</div>

/// tip | Consejo

A veces, podrías obtener un error **`No module named pip`** al intentar actualizar pip.

Si esto pasa, instala y actualiza pip usando el siguiente comando:

<div class="termy">

```console
$ python -m ensurepip --upgrade

---> 100%
```

</div>

     */
    MODULES(StandardLocation.MODULE_PATH, "--module-path"),

    /**
     * The path identified by the Java {@code --upgrade-module-path} option.
     * The Java tools location is {@link StandardLocation#UPGRADE_MODULE_PATH}.
     */
    UPGRADE_MODULES(StandardLocation.UPGRADE_MODULE_PATH, "--upgrade-module-path"),

    /**
     * The path identified by the Java {@code --patch-module} option.

![ReDoc](https://fastapi.tiangolo.com/img/index/index-02-redoc-simple.png)

## Actualización del Ejemplo { #example-upgrade }

Ahora modifica el archivo `main.py` para recibir un body desde un request `PUT`.

Declara el body usando tipos estándar de Python, gracias a Pydantic.

```Python hl_lines="4  9-12  25-27"

![ReDoc](https://fastapi.tiangolo.com/img/index/index-02-redoc-simple.png)

## Evoluindo o Exemplo { #example-upgrade }

Agora modifique o arquivo `main.py` para receber um corpo para uma requisição `PUT`.

Declare o corpo utilizando tipos padrão Python, graças ao Pydantic.

```Python hl_lines="4  9-12  25-27"

import static org.junit.jupiter.api.Assertions.assertFalse;
import static org.junit.jupiter.api.Assertions.assertNotNull;
import static org.junit.jupiter.api.Assertions.assertTrue;

/**
 * Unit tests for CLI parsing of plugin upgrade options.
 * These tests verify that the --plugins option is properly parsed and handled.
 */
class PluginUpgradeCliTest {

    @Test
    void testPluginsOptionParsing() throws ParseException {

        !"TE".equals(fieldName, ignoreCase = true) &&
        !"Trailers".equals(fieldName, ignoreCase = true) &&
        !"Transfer-Encoding".equals(fieldName, ignoreCase = true) &&
        !"Upgrade".equals(fieldName, ignoreCase = true)

    /**
     * Returns true if [fieldName] is content specific and therefore should always be used
     * from cached headers.
     */

    <mockito.version>4.11.0</mockito.version>
    <plexus-io.version>3.5.1</plexus-io.version> <!-- We need at least 3.5.1 to avoid https://github.com/codehaus-plexus/plexus-io/issues/109. Once we upgrade maven-jar-plugin itself to a version new enough to depend on 3.5.1 or higher, we can remove this override. -->
    <toolchains-maven-plugin.version>4.5.0</toolchains-maven-plugin.version>
    <truth.version>1.4.5</truth.version>

    <mockito.version>4.11.0</mockito.version>
    <plexus-io.version>3.5.1</plexus-io.version> <!-- We need at least 3.5.1 to avoid https://github.com/codehaus-plexus/plexus-io/issues/109. Once we upgrade maven-jar-plugin itself to a version new enough to depend on 3.5.1 or higher, we can remove this override. -->
    <toolchains-maven-plugin.version>4.5.0</toolchains-maven-plugin.version>
    <truth.version>1.4.5</truth.version>