* [reader]. For example, if the reader's peeked tag isn't readable by this adapter, it may return
   * a default value.
   *
   * If this does read a value, it starts with the tag and length, and reads an entire value,
   * including any potential composed values.
   *
   * If there's nothing to read and no default value, this will throw an exception.
   */
  fun fromDer(reader: DerReader): T

Crea metadata para tus etiquetas y pásala al parámetro `openapi_tags`:

{* ../../docs_src/metadata/tutorial004_py39.py hl[3:16,18] *}

Nota que puedes utilizar Markdown dentro de las descripciones, por ejemplo "login" se mostrará en negrita (**login**) y "fancy" se mostrará en cursiva (_fancy_).

/// tip | Consejo

No tienes que agregar metadata para todas las etiquetas que uses.

///

```

////

Você declara a dependência como o tipo do parâmetro, e utiliza `Depends()` sem nenhum parâmetro, em vez de ter que escrever a classe *novamente* dentro de `Depends(CommonQueryParams)`.

O mesmo exemplo ficaria então dessa forma:

{* ../../docs_src/dependencies/tutorial004_an_py310.py hl[19] *}

...e o **FastAPI** saberá o que fazer.

/// tip | Dica

<div class="termy">

```console
// Go to the home directory
$ cd
// Create a directory for all your code projects
$ mkdir code
// Enter into that code directory
$ cd code
// Create a directory for this project
$ mkdir awesome-project
// Enter into that project directory
$ cd awesome-project
```

</div>

## Create a Virtual Environment { #create-a-virtual-environment }

    assertNull(getMap().get(k1()));
    assertEquals(k1(), getMap().inverse().get(null));
    assertEquals(1, getMap().size());
  }

  // nb: inverse is run through its own entire suite

  @MapFeature.Require(SUPPORTS_PUT)
  @CollectionSize.Require(ZERO)
  public void testInversePut() {
    getMap().put(k0(), v0());
    getMap().inverse().put(v1(), k1());
    expectAdded(e0(), e1());

     * be unmarshalled.
     *
     * @param configuration The configuration to unmarshal, may be {@code null}.
     * @param element Configuration element name to unmarshal or {@code null} to unmarshal entire configuration.
     * @return This request for chaining, never {@code null}.
     */
    BeanConfigurationRequest setConfiguration(Object configuration, String element);

    /**

         * typically set by Maven itself and flagged as readOnly=true or by users via maven-system.properties files.
         * System properties are initialized before the build starts and are available throughout the entire Maven
         * execution. They are used for core Maven functionality that needs to be established at startup.
         */
        SYSTEM_PROPERTIES,
        /**

## Injetar o usuário atual { #inject-the-current-user }

Então agora nós podemos usar o mesmo `Depends` com nosso `get_current_user` na *operação de rota*:

{* ../../docs_src/security/tutorial002_an_py310.py hl[31] *}

Observe que nós declaramos o tipo de `current_user` como o modelo Pydantic `User`.

Isso nos ajudará dentro da função com todo o preenchimento automático e verificações de tipo.

/// tip | Dica

         *
         * @return the length in bytes of the entire notification response
         */
        public int getLength() {
            return length;
        }

        /**
         * Sets the total length of the notification response.
         *
         * @param length the length in bytes of the entire notification response
         */
        public void setLength(int length) {

from datetime import date

from pydantic import BaseModel

# Declare uma variável como str
# e obtenha suporte do editor dentro da função
def main(user_id: str):
    return user_id


# Um modelo do Pydantic
class User(BaseModel):
    id: int
    name: str
    joined: date
```

Que então pode ser usado como:

```Python
my_user: User = User(id=3, name="John Doe", joined="2018-07-19")

second_user_data = {