* NullPointerException if the comparator does. Since our construction
   * methods ensure that null is never present in the map, it's OK for the
   * comparator to look for it wherever it wants.
   *
   * Note that we do NOT touch the comparator returned by comparator(), which
   * should be identical to the one the user passed in. We touch only the
   * "secret" comparator used by the delegate implementation.
   */

Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing,...

また、受け取ったパスワードが保存されているハッシュと一致するかどうかを検証するユーティリティも作成します。

さらに、ユーザーを認証して返す関数も作成します。

```Python hl_lines="7  48  55-56  59-60  69-75"
{!../../docs_src/security/tutorial004.py!}
```

/// note | "備考"

新しい（偽の）データベース`fake_users_db`を確認すると、ハッシュ化されたパスワードが次のようになっていることがわかります：`"$2b$12$EixZaYVK1fsbw1ZfbX3OXePaWxn96p36WQoeG6Lruj3vjPGga31lW"`

///

## JWTトークンの取り扱い

インストールした複数のモジュールをインポートします。

	kexAlgoDH14SHA256, kexAlgoDH16SHA512, kexAlgoDH14SHA1,
	kexAlgoDH1SHA1,
}

// supportedPubKeyAuthAlgos specifies the supported client public key
// authentication algorithms. Note that this doesn't include certificate types
// since those use the underlying algorithm. This list is sent to the client if
// it supports the server-sig-algs extension. Order is irrelevant.

func (n *NetworkError) Unwrap() error {
	return n.Err
}

// Client - http based RPC client.
type Client struct {
	connected int32 // ref: https://golang.org/pkg/sync/atomic/#pkg-note-BUG
	_         int32 // For 64 bits alignment
	lastConn  int64

	// HealthCheckFn is the function set to test for health.
	// If not set the client will not keep track of health.

**FastAPI** повністю базується на цих анотаціях типів, вони дають йому багато переваг.

Але навіть якщо ви ніколи не використаєте **FastAPI**, вам буде корисно дізнатись трохи про них.

/// note

Якщо ви експерт у Python і ви вже знаєте усе про анотації типів - перейдіть до наступного розділу.

///

## Мотивація

Давайте почнемо з простого прикладу:

```Python

通过声明变量的类型，编辑器和一些工具能给你提供更好的支持。

这只是一个关于 Python 类型提示的**快速入门 / 复习**。它仅涵盖与 **FastAPI** 一起使用所需的最少部分...实际上只有很少一点。

整个 **FastAPI** 都基于这些类型提示构建，它们带来了许多优点和好处。

但即使你不会用到 **FastAPI**，了解一下类型提示也会让你从中受益。

/// note

如果你已经精通 Python，并且了解关于类型提示的一切知识，直接跳到下一章节吧。

///

## 动机

让我们从一个简单的例子开始：

```Python
{!../../docs_src/python_types/tutorial001.py!}
```

运行这段程序将输出：

```
John Doe
```

	//	#define A(x)
	// and
	//	#define A (x)
	// distinctly: the first is a macro with arguments, the second without.
	// Distinguish these cases using the column number, since we don't
	// see the space itself. Note that text/scanner reports the position at the
	// end of the token. It's where you are now, and you just read this token.
	if tok == '(' && in.Stack.Col() == prevCol+1 {
		// Macro has arguments. Scan list of formals.

 */
internal class FastFallbackExchangeFinderTest {
  private val taskFaker = TaskFaker()
  private val taskRunner = taskFaker.taskRunner

  /**
   * Note that we don't use the same [TaskFaker] for this factory. That way off-topic tasks like
   * connection pool maintenance tasks don't add noise to route planning tests.
   */

   * {@code iterator().remove()} of an unmodifiable list could throw either {@link
   * IllegalStateException} or {@link UnsupportedOperationException}. Note that iterator
   * implementations should always throw one of the exceptions in a {@code PermittedExceptions}
   * instance, since {@code PermittedExceptions} is thrown only when a method call is invalid.
   *