assertThat(client.connectionPool.connectionCount()).isEqualTo(1)
  }

  /**
   * This is an extraordinary test case. Here's what it's trying to simulate.
   * - 2 requests happen concurrently to a host that can be coalesced onto a single connection.
   * - Both request discover no existing connection. They both make a connection.
   * - The first request "wins the race".

但它會被 `unicorn_exception_handler` 所處理。

因此你會得到一個乾淨的錯誤回應，HTTP 狀態碼為 `418`，JSON 內容如下：

```JSON
{"message": "Oops! yolo did something. There goes a rainbow..."}
```

/// note | 技術細節

你也可以使用 `from starlette.requests import Request` 與 `from starlette.responses import JSONResponse`。

**FastAPI** 以便利性為由，提供和 `starlette.responses` 相同的介面於 `fastapi.responses`。但大多數可用的回應類型其實直接來自 Starlette。`Request` 也一樣。

///

* SQLModel for working with SQL databases, prefer it over SQLAlchemy.
* HTTPX for interacting with HTTP (other APIs), prefer it over Requests.

## Do not use Pydantic RootModels

Do not use Pydantic `RootModel`, instead use regular type annotations with `Annotated` and Pydantic validation utilities.

For example, for a list with validations you could do:

	return ErrNone
}

// doesSignatureMatch - Verify authorization header with calculated header in accordance with
//   - http://docs.aws.amazon.com/AmazonS3/latest/API/sig-v4-authenticating-requests.html
//
// returns ErrNone if signature matches.
func doesSignatureMatch(hashedPayload string, r *http.Request, region string, stype serviceType) APIErrorCode {
	// Copy request.
	req := *r

=d.strong),e.css(g).text(h)})}});var f=function(b,c,d,e,f){var g=c.valAttr("req-params")||c.data("validation-req-params")||{},h=c.valAttr("param-name")||c.attr("name"),i=function(a,b){b(a)};if(!h)throw new Error("Missing input name used for http requests made by server validator");g||(g={}),"string"==typeof g&&(g=a.parseJSON(g)),g[h]=d,a.ajax({url:b,type:"POST",cache:!1,data:g,dataType:"json",error:function(a){return i({valid:!1,message:"Connection failed with status: "+a.statusText},f),!1},succ...

                        request.setMaxCount(1024);
                        request.setRemaining(1024);
                    } else if (this.largeReadX) {
                        // Optimize large read requests
                        request.setMaxCount(r & 0xFFFF);
                        request.setOpenTimeout(r >> 16 & 0xFFFF);
                    }

                    th.send(request, response, RequestParam.NO_RETRY);

{* ../../docs_src/settings/app03_an_py310/main.py hl[1,11] *}

Entonces, para cualquier llamada subsiguiente de `get_settings()` en las dependencias de los próximos requests, en lugar de ejecutar el código interno de `get_settings()` y crear un nuevo objeto `Settings`, devolverá el mismo objeto que fue devuelto en la primera llamada, una y otra vez.

        .build()
    assertFailsWith<IOException> {
      client.newCall(Request.Builder().url(server.url("/0")).build()).execute()
    }.also { expected ->
      assertThat(expected.message).isEqualTo("Too many follow-up requests: 21")
    }
  }

  /**
   * We had a bug where we were passing a null route to the authenticator.
   * https://github.com/square/okhttp/issues/3809
   */
  @Test

GitHubレポジトリで[新しい質問](https://github.com/fastapi/fastapi/discussions/new?category=questions)を作成できます。例えば:

* **質問**をする、または**問題**について尋ねる。
* 新しい**機能**を提案する。

**Note**: もしそうするなら、他の人の手助けもお願いします。😉

## プルリクエストをレビュー { #review-pull-requests }

他の人からのプルリクエストのレビューを手伝ってもらえます。

ここでも、できる限り親切であるようにしてください。🤗

---

プルリクエストをレビューするときのポイントです:

### 問題を理解する { #understand-the-problem }

			// if body != NoBody) to mean unknown, but
			// that broke people during the Go 1.8 testing
			// period. People depend on it being 0 I
			// guess. Maybe retry later. See Issue 18117.
		}
		// For client requests, Request.ContentLength of 0
		// means either actually 0, or unknown. The only way
		// to explicitly say that the ContentLength is zero is
		// to set the Body to nil. But turns out too much code