errDecommissionRebalanceAlreadyRunning = errors.New("Decommission cannot be started, rebalance is already in progress")
)

func (a adminAPIHandlers) StartDecommission(w http.ResponseWriter, r *http.Request) {
	ctx := r.Context()

	objectAPI, _ := validateAdminReq(ctx, w, r, policy.DecommissionAdminAction)
	if objectAPI == nil {
		return
	}

from fastapi.websockets import WebSocket
from starlette.exceptions import HTTPException
from starlette.requests import Request
from starlette.responses import JSONResponse, Response
from starlette.status import HTTP_422_UNPROCESSABLE_ENTITY, WS_1008_POLICY_VIOLATION


async def http_exception_handler(request: Request, exc: HTTPException) -> Response:
    headers = getattr(exc, "headers", None)

</div>

## Using `Jinja2Templates`

* Import `Jinja2Templates`.
* Create a `templates` object that you can reuse later.
* Declare a `Request` parameter in the *path operation* that will return a template.
* Use the `templates` you created to render and return a `TemplateResponse`, pass the name of the template, the request object, and a "context" dictionary with key-value pairs to be used inside of the Jinja2 template.

```Python hl_lines="4  11  15-18"

* 导入 `Jinja2Templates`
* 创建可复用的 `templates` 对象
* 在返回模板的*路径操作*中声明 `Request` 参数
* 使用 `templates` 渲染并返回 `TemplateResponse`， 传递模板的名称、request对象以及一个包含多个键值对（用于Jinja2模板）的"context"字典，

```Python hl_lines="4  11  15-16"
{!../../docs_src/templates/tutorial001.py!}
```

/// note | "笔记"

在FastAPI 0.108.0，Starlette 0.29.0之前，`name`是第一个参数。
并且，在此之前，`request`对象是作为context的一部分以键值对的形式传递的。

///

/// tip | "提示"

            ModelBuildingRequest request,
            ModelProblemCollector problems) {
        model.update(
                injectProfile(model.getDelegate(), profile != null ? profile.getDelegate() : null, request, problems));
    }

    @Override
    public Model injectProfile(
            Model model, Profile profile, ModelBuildingRequest request, ModelProblemCollector problems) {

		query := url.Values{}
		for key, value := range testCase.queryParams {
			query.Set(key, value)
		}
		// Create a request to use.
		req, err := http.NewRequest(http.MethodGet, "http://host/a/b?"+query.Encode(), nil)
		if err != nil {
			t.Errorf("(%d) failed to create http.Request, got %v", i, err)
		}
		if testCase.expected != ErrNone {
			// Should be set since we are simulating a http server.

A "middleware" is a function that works with every **request** before it is processed by any specific *path operation*. And also with every **response** before returning it.

* It takes each **request** that comes to your application.
* It can then do something to that **request** or run any needed code.
* Then it passes the **request** to be processed by the rest of the application (by some *path operation*).

## Usando `Jinja2Templates`

* Importe `Jinja2Templates`.
* Crie um `templates` que você possa reutilizar posteriormente.
* Declare um parâmetro `Request` no *path operation* que retornará um template.
* Use o `template` que você criou para renderizar e retornar uma `TemplateResponse`, passe o nome do template, o request object, e um "context" dict com pares chave-valor a serem usados dentro do template do Jinja2.

```Python hl_lines="4  11  15-18"

from fastapi import FastAPI
from fastapi.middleware.wsgi import WSGIMiddleware
from flask import Flask, request
from markupsafe import escape

flask_app = Flask(__name__)


@flask_app.route("/")
def flask_main():
    name = request.args.get("name", "World")
    return f"Hello, {escape(name)} from Flask!"


app = FastAPI()


@app.get("/v2")
def read_main():
    return {"message": "Hello World"}

            }

            request.setToolchains(groupedToolchains);
        }
        return request;
    }

    @Override
    public MavenExecutionRequest populateDefaults(MavenExecutionRequest request)
            throws MavenExecutionRequestPopulationException {
        baseDirectory(request);

        localRepository(request);

        populateDefaultPluginGroups(request);

        return request;
    }