* {@code A -> B}.
   *
   * @since 9.0 (in 1.0 as {@code com.google.common.base.Service.State})
   */
  enum State {
    /** A service in this state is inactive. It does minimal work and consumes minimal resources. */
    NEW,

    /** A service in this state is transitioning to {@link #RUNNING}. */
    STARTING,

    /** A service in this state is operational. */
    RUNNING,

实际上，忽略这个附加响应头，也不会有什么问题。

之所以在此提供这个附加响应头，是为了符合规范的要求。

说不定什么时候，就有工具用得上它，而且，开发者或用户也可能用得上。

这就是遵循标准的好处……

///

## 实际效果

打开 API 文档：<a href="http://127.0.0.1:8000/docs" class="external-link" target="_blank">http://127.0.0.1:8000/docs</a>。

### 身份验证

点击**Authorize**按钮。

使用以下凭证：

用户名：`johndoe`

密码：`secret`

<img src="https://fastapi.tiangolo.com/img/tutorial/security/image04.png">

 * <ul>
 *     <li>{@code jar}: Packages the project as a Java Archive (JAR) file.</li>
 *     <li>{@code war}: Packages the project as a Web Application Archive (WAR) file.</li>
 *     <li>{@code pom}: Indicates that the project does not produce a deployable artifact but is used for dependency management or as an aggregator.</li>
 *     <li>{@code maven-plugin}: Packages the project as a Maven plugin.</li>
 * </ul>
 *
 * <h2>Usage Example</h2>
 *

Wenn Sie mehr über Formularfelder und ihre Kodierungen lesen möchten, besuchen Sie die <a href="https://developer.mozilla.org/en-US/docs/Web/HTTP/Methods/POST" class="external-link" target="_blank"><abbr title="Mozilla Developer Network – Mozilla-Entwickler-Netzwerk">MDN</abbr>-Webdokumentation für <code>POST</code></a>.

///

/// warning | "Achtung"

  private transient Map<K, KeyList<K, V>> keyToKeyList;
  private transient int size;

  /*
   * Tracks modifications to keyToKeyList so that addition or removal of keys invalidates
   * preexisting iterators. This does *not* track simple additions and removals of values
   * that are not the first to be added or last to be removed for their key.
   */
  private transient int modCount;

/* jcifs smb client library in Java
 * Copyright (C) 2000  "Michael B. Allen" <jcifs at samba dot org>
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,

/* jcifs smb client library in Java
 * Copyright (C) 2000  "Michael B. Allen" <jcifs at samba dot org>
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,

/* jcifs msrpc client library in Java
 * Copyright (C) 2007  "Michael B. Allen" <jcifs at samba dot org>
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,

/* jcifs smb client library in Java
 * Copyright (C) 2005  "Michael B. Allen" <jcifs at samba dot org>
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,

/* jcifs smb client library in Java
 * Copyright (C) 2000  "Michael B. Allen" <jcifs at samba dot org>
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 * 
 * This library is distributed in the hope that it will be useful,