public final double sampleCovariance() {
    checkState(count() > 1);
    return sumOfProductsOfDeltas / (count() - 1);
  }

  /**
   * Returns the <a href="http://mathworld.wolfram.com/CorrelationCoefficient.html">Pearson's or
   * product-moment correlation coefficient</a> of the values. The count must greater than one, and
   * the {@code x} and {@code y} values must both have non-zero population variance (i.e. {@code

# Paramètres de chemin

Vous pouvez déclarer des "paramètres" ou "variables" de chemin avec la même syntaxe que celle utilisée par le
<a href="https://docs.python.org/fr/3/library/string.html#format-string-syntax" class="external-link" target="_blank">formatage de chaîne Python</a> :


```Python hl_lines="6-7"
{!../../docs_src/path_params/tutorial001.py!}
```

La valeur du paramètre `item_id` sera transmise à la fonction dans l'argument `item_id`.

  private static final SecretKey SHA512_KEY =
      new SecretKeySpec("secret key".getBytes(UTF_8), "HmacSHA512");

  // From http://docs.oracle.com/javase/7/docs/technotes/guides/security/StandardNames.html#Mac
  private static final ImmutableTable<String, SecretKey, HashFunction> ALGORITHMS =
      new ImmutableTable.Builder<String, SecretKey, HashFunction>()
          .put("HmacMD5", MD5_KEY, Hashing.hmacMd5(MD5_KEY))

///

`status_code` 🔢 📨 🔢 ⏮️ 🇺🇸🔍 👔 📟.

/// info

`status_code` 💪 👐 📨 `IntEnum`, ✅ 🐍 <a href="https://docs.python.org/3/library/http.html#http.HTTPStatus" class="external-link" target="_blank">`http.HTTPStatus`</a>.

///

⚫️ 🔜:

* 📨 👈 👔 📟 📨.
* 📄 ⚫️ ✅ 🗄 🔗 ( &amp; , 👩‍💻 🔢):

<img src="/img/tutorial/response-status-code/image01.png">

package s3select

import "strings"

// SelectError - represents s3 select error specified in
// https://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectSELECTContent.html#RESTObjectSELECTContent-responses-special-errors.
type SelectError interface {
	Cause() error
	ErrorCode() string
	ErrorMessage() string
	HTTPStatusCode() int
	Error() string
}

type s3Error struct {

    private const val TRANSFER_ENCODING = "transfer-encoding"
    private const val TE = "te"
    private const val ENCODING = "encoding"
    private const val UPGRADE = "upgrade"

    /** See http://tools.ietf.org/html/draft-ietf-httpbis-http2-09#section-8.1.3. */
    private val HTTP_2_SKIPPED_REQUEST_HEADERS =
      immutableListOf(
        CONNECTION,
        HOST,
        KEEP_ALIVE,
        PROXY_CONNECTION,
        TE,

 *  * If `server_max_window_bits` is less than 15, OkHttp will waste memory on an oversized buffer.
 *
 * See [RFC 7692, 7.1][rfc_7692] for details on negotiation process.
 *
 * [rfc_7692]: https://tools.ietf.org/html/rfc7692#section-7.1
 */
@IgnoreJRERequirement // As of AGP 3.4.1, D8 desugars API 24 hashCode methods.
data class WebSocketExtensions(
  /** True if the agreed upon extensions includes the permessage-deflate extension. */

注意，`status_code` 是（`get`、`post` 等）**装饰器**方法中的参数。与之前的参数和请求体不同，不是*路径操作函数*的参数。

///

`status_code` 参数接收表示 HTTP 状态码的数字。

/// info | "说明"

`status_code` 还能接收 `IntEnum` 类型，比如 Python 的 <a href="https://docs.python.org/3/library/http.html#http.HTTPStatus" class="external-link" target="_blank">`http.HTTPStatus`</a>。

///

它可以：

* 在响应中返回状态码
* 在 OpenAPI 概图（及用户界面）中存档：

<img src="/img/tutorial/response-status-code/image01.png">

<%@page pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%>
<la:form action="/search" method="get" styleId="searchForm"
	role="search">
	${fe:facetForm()}${fe:geoForm()}
	<header>
		<nav class="navbar navbar-expand-md navbar-dark fixed-top bg-dark">
			<div id="content" class="container">
				<la:link styleClass="navbar-brand d-inline-flex" href="/">
					<img src="${fe:url('/images/logo-head.png')}"

<%@page pageEncoding="UTF-8" contentType="text/html; charset=UTF-8"%>
<la:form action="/search" method="get" styleId="searchForm"
	role="search">
	${fe:facetForm()}${fe:geoForm()}
	<header>
		<nav class="navbar navbar-expand-md navbar-dark fixed-top bg-dark">
			<div id="content" class="container">
				<la:link styleClass="navbar-brand d-inline-flex" href="/">
					<img src="${fe:url('/images/logo-head.png')}"