private:
  // Uses "v2_reader_" to build "var name -> shape" and "var name -> data type"
  // maps; both owned by caller.
  // REQUIRES: "v2_reader_ != nullptr && v2_reader_.status().ok()".
  std::pair<std::unique_ptr<TensorSliceReader::VarToShapeMap>,
            std::unique_ptr<TensorSliceReader::VarToDataTypeMap> >
  BuildV2VarMaps();

  // Invariant: exactly one of "reader_" and "v2_reader_" is non-null.

# Header Parameters

You can define Header parameters the same way you define `Query`, `Path` and `Cookie` parameters.

## Import `Header`

First import `Header`:

=== "Python 3.10+"

    ```Python hl_lines="3"
    {!> ../../../docs_src/header_params/tutorial001_an_py310.py!}
    ```

=== "Python 3.9+"

    ```Python hl_lines="3"
    {!> ../../../docs_src/header_params/tutorial001_an_py39.py!}
    ```

=== "Python 3.8+"

## importe `Header`

Primeiro importe `Header`:

=== "Python 3.10+"

    ```Python hl_lines="1"
    {!> ../../../docs_src/header_params/tutorial001_py310.py!}
    ```

=== "Python 3.8+"

    ```Python hl_lines="3"
    {!> ../../../docs_src/header_params/tutorial001.py!}
    ```

## Declare parâmetros de `Header`

# This service account aggregates reader permissions for the revisions in a given cluster
# Should be used for remote secret creation.
apiVersion: v1
kind: ServiceAccount
  {{- if .Values.global.imagePullSecrets }}
imagePullSecrets:
  {{- range .Values.global.imagePullSecrets }}
  - name: {{ . }}
    {{- end }}
    {{- end }}
metadata:
  name: istio-reader-service-account
  namespace: {{ .Values.global.istioNamespace }}
  labels:

  public static class Chars extends SampleElements<Character> {
    public Chars() {
      // elements aren't sorted, to better test SortedSet iteration ordering
      super('b', 'a', 'c', 'd', 'e');
    }
  }

  public static class Enums extends SampleElements<AnEnum> {
    public Enums() {
      // elements aren't sorted, to better test SortedSet iteration ordering
      super(AnEnum.B, AnEnum.A, AnEnum.C, AnEnum.D, AnEnum.E);
    }
  }

  public static class Chars extends SampleElements<Character> {
    public Chars() {
      // elements aren't sorted, to better test SortedSet iteration ordering
      super('b', 'a', 'c', 'd', 'e');
    }
  }

  public static class Enums extends SampleElements<AnEnum> {
    public Enums() {
      // elements aren't sorted, to better test SortedSet iteration ordering
      super(AnEnum.B, AnEnum.A, AnEnum.C, AnEnum.D, AnEnum.E);
    }
  }

		* Mas precisa de autenticação para aquele endpoint em específico.
		* Então, para autenticar com nossa API, ele manda um header de `Autorização` com o valor `Bearer` mais o token.
		* Se o token contém `foobar`, o conteúdo do header de `Autorização` será: `Bearer foobar`.

## **FastAPI**'s `OAuth2PasswordBearer`

            headers={"WWW-Authenticate": "Bearer"},
        )
    access_token_expires = timedelta(minutes=ACCESS_TOKEN_EXPIRE_MINUTES)
    access_token = create_access_token(
        data={"sub": user.username}, expires_delta=access_token_expires
    )
    return Token(access_token=access_token, token_type="bearer")


@app.get("/users/me/", response_model=User)

from pydantic import BaseModel
from typing_extensions import Annotated

app = FastAPI()

bearer_scheme = HTTPBearer()


class Subscription(BaseModel):
    username: str
    monthly_fee: float
    start_date: datetime


@app.webhooks.post("new-subscription")
def new_subscription(
    body: Subscription, token: Annotated[str, Security(bearer_scheme)]
):
    """

    - 为指定的端点（Endpoint）进行身份验证
    - 因此，用 API 验证身份时，要发送值为 `Bearer` + 令牌的请求头 `Authorization`
    - 假如令牌为 `foobar`，`Authorization` 请求头就是： `Bearer foobar`

## **FastAPI** 的 `OAuth2PasswordBearer`

**FastAPI** 提供了不同抽象级别的安全工具。

本例使用 **OAuth2** 的 **Password** 流以及 **Bearer** 令牌（`Token`）。为此要使用 `OAuth2PasswordBearer` 类。

!!! info "说明"

    `Bearer` 令牌不是唯一的选择。

    但它是最适合这个用例的方案。