Se não souber, você aprenderá o que é uma "senha hash" nos [capítulos de segurança](security/simple-oauth2.md#password-hashing){.internal-link target=_blank}.

///

## Múltiplos modelos

Aqui está uma ideia geral de como os modelos poderiam parecer com seus campos de senha e os lugares onde são usados:

//// tab | Python 3.8 and above

```Python hl_lines="9  11  16  22  24  29-30  33-35  40-41"

     */
    open fun header(
      name: String,
      value: String,
    ) = commonHeader(name, value)

    /**
     * Adds a header with [name] to [value]. Prefer this method for multiply-valued
     * headers like "Set-Cookie".
     */
    open fun addHeader(
      name: String,
      value: String,
    ) = commonAddHeader(name, value)

    // This class can make no hard guarantees.  The methods in this class are inherently flaky, but
    // we try hard to make them robust in practice.  We could additionally try to add in a system
    // load timeout multiplier.  Or we could try to use a CPU time bound instead of wall clock time
    // bound.  But these ideas are harder to implement.  We do not try to detect or handle a
    // user-specified -XX:+DisableExplicitGC.
    //

Mas em muitos casos, você desejará executar vários processos de trabalho ao mesmo tempo.

### Processos Múltiplos - Trabalhadores

Con **FastAPI** puedes aprovechar la concurrencia que es muy común para el desarrollo web (atractivo principal de NodeJS).

Pero también puedes aprovechar los beneficios del paralelismo y el multiprocesamiento (tener múltiples procesos ejecutándose en paralelo) para cargas de trabajo **CPU bound** como las de los sistemas de Machine Learning.

    // This class can make no hard guarantees.  The methods in this class are inherently flaky, but
    // we try hard to make them robust in practice.  We could additionally try to add in a system
    // load timeout multiplier.  Or we could try to use a CPU time bound instead of wall clock time
    // bound.  But these ideas are harder to implement.  We do not try to detect or handle a
    // user-specified -XX:+DisableExplicitGC.
    //

            options.addOption(Option.builder(THREADS)
                    .longOpt("threads")
                    .hasArg()
                    .desc("Thread count, for instance 4 (int) or 2C/2.5C (int/float) where C is core multiplied")
                    .build());
            options.addOption(Option.builder(BUILDER)
                    .longOpt("builder")
                    .hasArg()

```Python
commons: Annotated[dict, Depends(common_parameters)]
```

Mas como estamos utilizando `Annotated`, podemos guardar esse valor `Annotated` em uma variável e utilizá-la em múltiplos locais:

//// tab | Python 3.10+

```Python hl_lines="12  16  21"
{!> ../../docs_src/dependencies/tutorial001_02_an_py310.py!}
```

////

//// tab | Python 3.9+

        options.addOption(Option.builder(THREADS)
                .longOpt("threads")
                .hasArg()
                .desc("Thread count, for instance 4 (int) or 2C/2.5C (int/float) where C is core multiplied")
                .build());
        options.addOption(Option.builder(BUILDER)
                .longOpt("builder")
                .hasArg()
                .desc("The id of the build strategy to use")

    # A Vocabulary for Structural Validation
    type: Optional[str] = None
    enum: Optional[List[Any]] = None
    const: Optional[Any] = None
    multipleOf: Optional[float] = Field(default=None, gt=0)
    maximum: Optional[float] = None
    exclusiveMaximum: Optional[float] = None
    minimum: Optional[float] = None
    exclusiveMinimum: Optional[float] = None