* `allow_credentials` - 교차-출처 요청시 쿠키 지원 여부를 설정합니다. 기본값은 `False` 입니다. 또한 해당 항목을 허용할 경우 `allow_origins` 는 `['*']` 로 설정할 수 없으며, 출처를 반드시 특정해야 합니다.
* `expose_headers` - 브라우저에 접근할 수 있어야 하는 모든 응답 헤더를 가리킵니다. 기본값은 `[]` 입니다.
* `max_age` - 브라우저가 CORS 응답을 캐시에 저장하는 최대 시간을 초 단위로 설정합니다. 기본값은 `600` 입니다.

미들웨어는 두가지 특정한 종류의 HTTP 요청에 응답합니다...

### CORS 사전 요청

  /**
   * Tag interface marking trusted subclasses. This enables some optimizations. The implementation
   * of this interface must also be an AbstractFuture and must not override or expose for overriding
   * any of the public methods of ListenableFuture.
   */
  interface Trusted<V extends @Nullable Object> extends ListenableFuture<V> {}

* `expose_headers` - Указывает любые заголовки ответа, которые должны быть доступны браузеру. По умолчанию равно `[]`.

 * Fix: Locking bug in SpdyConnection.
 * Fix: Ignore null header values (for compatibility with HttpURLConnection).
 * Add URLStreamHandlerFactory support so that `URL.openConnection()` uses
   OkHttp.
 * Expose the transport ("http/1.1", "spdy/3", etc.) via magic request headers.
   Use `X-Android-Transports` to write the preferred transports and
   `X-Android-Selected-Transport` to read the negotiated transport.

// negate negates a numeric value
func (v *Value) negate() {
	switch x := v.value.(type) {
	case float64:
		v.value = -x
	case int64:
		v.value = -x
	}
}

// Value comparison functions: we do not expose them outside the
// module. Logical operators "<", ">", ">=", "<=" work on strings and
// numbers. Equality operators "=", "!=" work on strings,
// numbers and booleans.

// Supported comparison operators
const (

Dans ce cas, votre `Dockerfile` pourrait ressembler à ceci :

```Dockerfile
FROM python:3.7

RUN pip install fastapi uvicorn

EXPOSE 80

COPY ./app /app

CMD ["uvicorn", "app.main:app", "--host", "0.0.0.0", "--port", "80"]
```

## Créer le code **FastAPI**.

* Créer un répertoire `app` et y entrer.
* Créez un fichier `main.py` avec :

    <exportedPackage>jakarta.annotation.*</exportedPackage>

    <!--
      | We may potentially want to export these, but right now I'm not sure that anything Guice specific needs
      | to be made available to plugin authors. If we find people are getting fancy and want to take advantage of
      | Guice specifics we can expose that later. Really some testing needs to be done to see full hiding

* `allow_credentials` - 🎦 👈 🍪 🔜 🐕‍🦺 ✖️-🇨🇳 📨. 🔢 `False`. , `allow_origins` 🚫🔜 ⚒ `['*']` 🎓 ✔, 🇨🇳 🔜 ✔.
* `expose_headers` - 🎦 🙆 📨 🎚 👈 🔜 ⚒ ♿ 🖥. 🔢 `[]`.
* `max_age` - ⚒ 🔆 🕰 🥈 🖥 💾 ⚜ 📨. 🔢 `600`.

🛠️ 📨 2️⃣ 🎯 🆎 🇺🇸🔍 📨...

### ⚜ 🛫 📨

👉 🙆 `OPTIONS` 📨 ⏮️ `Origin` & `Access-Control-Request-Method` 🎚.

func (c *minioCollector) Describe(ch chan<- *prometheus.Desc) {
	ch <- c.desc
}

// Collect is called by the Prometheus registry when collecting metrics.
func (c *minioCollector) Collect(ch chan<- prometheus.Metric) {
	// Expose MinIO's version information
	minioVersionInfo.WithLabelValues(Version, CommitID).Set(1.0)

	storageMetricsPrometheus(ch)
	nodeHealthMetricsPrometheus(ch)
	bucketUsageMetricsPrometheus(ch)

    try {
      ImmutableLongArray.builder(-1);
      fail();
    } catch (IllegalArgumentException expected) {
    }
  }

  /**
   * If there's a bug in builder growth, we wouldn't know how to expose it. So, brute force the hell
   * out of it for a while and see what happens.
   */
  public void testBuilder_bruteForce() {
    for (int i = 0; i < reduceIterationsIfGwt(100); i++) {