* topological sort) that only need a way of accessing the predecessors of a node in a graph.
 *
 * <h3>Usage</h3>
 *
 * Given an algorithm, for example:
 *
 * <pre>{@code
 * public <N> someGraphAlgorithm(N startNode, PredecessorsFunction<N> predecessorsFunction);
 * }</pre>
 *
 * you will invoke it depending on the graph representation you're using.
 *

 * href="http://en.wikipedia.org/wiki/Decorator_pattern">decorator pattern</a>.
 *
 * <p><b>Warning:</b> The methods of {@code ForwardingMapEntry} forward <i>indiscriminately</i> to
 * the methods of the delegate. For example, overriding {@link #getValue} alone <i>will not</i>
 * change the behavior of {@link #equals}, which can lead to unexpected behavior. In this case, you

这个操作一般只需要在最开始执行一次。

/// tip

域名这部分发生在 HTTPS 之前，由于这一切都依赖于域名和 IP 地址，所以先在这里提一下。

///

### DNS

现在让我们关注真正的 HTTPS 部分。

首先，浏览器将通过 **DNS 服务器** 查询**域名的IP** 是什么，在本例中为 `someapp.example.com`。

DNS 服务器会告诉浏览器使用某个特定的 **IP 地址**。 这将是你在 DNS 服务器中为你的服务器配置的公共 IP 地址。

<img src="/img/deployment/https/https01.svg">

### TLS 握手开始

然后，浏览器将在**端口 443**（HTTPS 端口）上与该 IP 地址进行通信。

   * value. Otherwise, a call that passes one {@code loader} may return the result of another call
   * with a differently behaving {@code loader}. For example, a call that requests a short timeout
   * for an RPC may wait for a similar call that requests a long timeout, or a call by an
   * unprivileged user may return a resource accessible only to a privileged user making a similar

}

func Cmd(cliContext cli.Context) *cobra.Command {
	cmd := &cobra.Command{
		Use:     "injector",
		Short:   "List sidecar injector and sidecar versions",
		Long:    `List sidecar injector and sidecar versions`,
		Example: `  istioctl experimental injector list`,
		Args: func(cmd *cobra.Command, args []string) error {
			if len(args) != 0 {
				return fmt.Errorf("unknown subcommand %q", args[0])
			}
			return nil
		},

   * if the primary input succeeds, it is never invoked. If, during the invocation of {@code
   * fallback}, an exception is thrown, this exception is used as the result of the output {@code
   * Future}.
   *
   * <p>Usage example:
   *
   * <pre>{@code
   * ListenableFuture<Integer> fetchCounterFuture = ...;
   *
   * // Falling back to a zero counter in case an exception happens when
   * // processing the RPC to fetch counters.

                    method, className, CollectionUtils.join(", ", candidates));
            message += "\nThis problem may happen when some apilink from docbook template xmls is incorrect. Example:"
                    + "\nIncorrect: <apilink class=\"org.gradle.api.Project\" method=\"tarTree\"/>"
                    + "\nCorrect:   <apilink class=\"org.gradle.api.Project\" method=\"tarTree(Object)\"/>";

```Python hl_lines="11"
{!../../docs_src/handling_errors/tutorial001.py!}

```

### 响应结果

请求为 `http://example.com/items/foo`（`item_id` 为 `「foo」`）时，客户端会接收到 HTTP 状态码 - 200 及如下 JSON 响应结果：

```JSON
{
  "item": "The Foo Wrestlers"
}

```

但如果客户端请求 `http://example.com/items/bar`（`item_id` `「bar」` 不存在时），则会接收到 HTTP 状态码 - 404（「未找到」错误）及如下 JSON 响应结果：

```JSON
{
  "detail": "Item not found"
}

    "tax": 3.2,
    "tags": [
        "rock",
        "metal",
        "bar"
    ],
    "images": [
        {
            "url": "http://example.com/baz.jpg",
            "name": "The Foo live"
        },
        {
            "url": "http://example.com/dave.jpg",
            "name": "The Baz"
        }
    ]
}
```

/// info | "情報"

`images`キーが画像オブジェクトのリストを持つようになったことに注目してください。

 * will resolve the type parameters of the method or constructor in the context of the owner type,
 * which may be a subtype of the declaring class. For example:
 *
 * <pre>{@code
 * Method getMethod = List.class.getMethod("get", int.class);
 * Invokable<List<String>, ?> invokable = new TypeToken<List<String>>() {}.method(getMethod);