例えば、<a href="https://docs.python.org/3/tutorial/inputoutput.html#reading-and-writing-files" class="external-link" target="_blank">ファイルを読み込むには`with`を使用することができます</a>:

```Python
with open("./somefile.txt") as f:
    contents = f.read()
    print(contents)
```

その後の`open("./somefile.txt")`は「コンテキストマネージャ」と呼ばれるオブジェクトを作成します。

`with`ブロックが終了すると、例外があったとしてもファイルを確かに閉じます。

`yield`を依存関係を作成すると、**FastAPI** は内部的にそれをコンテキストマネージャに変換し、他の関連ツールと組み合わせます。

O **FastAPI** pegará o modelo do Pydantic, gerará o `JSON Schema`, e adicionará no local correto.

O local correto é:

* Na chave `content`, que tem como valor um outro objeto JSON (`dict`) que contém:
    * Uma chave com o media type, como por exemplo `application/json`, que contém como valor um outro objeto JSON, contendo::
        * Uma chave `schema`, que contém como valor o JSON Schema do modelo, sendo este o local correto.

        mergeModel_Developers(target, source, sourceDominant, context);
        mergeModel_Contributors(target, source, sourceDominant, context);
        mergeModel_IssueManagement(target, source, sourceDominant, context);
        mergeModel_Scm(target, source, sourceDominant, context);
        mergeModel_CiManagement(target, source, sourceDominant, context);
        mergeModel_Prerequisites(target, source, sourceDominant, context);

		r.writeCond = sync.NewCond(&r.mu)
	}
	return r
}

// WithCancel sets a context to cancel the ring buffer.
// When the context is canceled, the ring buffer will be closed with the context error.
// A goroutine will be started and run until the provided context is canceled.
func (r *RingBuffer) WithCancel(ctx context.Context) *RingBuffer {
	go func() {
		<-ctx.Done()
		r.CloseWithError(ctx.Err())
	}()
	return r
}

import jcifs.CIFSException;
import jcifs.Config;
import jcifs.config.PropertyConfiguration;
import jcifs.context.BaseContext;
import jcifs.netbios.UniAddress;
import jcifs.smb.NtlmPasswordAuthentication;
import jcifs.smb.SmbAuthException;

/**
 * This servlet may be used with pre-2.3 servlet containers
 * to protect content with NTLM HTTP Authentication. Servlets that
 * extend this abstract base class may be authenticated against an SMB

func (z *erasureServerPools) StorageInfo(ctx context.Context, metrics bool) StorageInfo {
	return globalNotificationSys.StorageInfo(ctx, z, metrics)
}

func (z *erasureServerPools) NSScanner(ctx context.Context, updates chan<- DataUsageInfo, wantCycle uint32, healScanMode madmin.HealScanMode) error {
	// Updates must be closed before we return.
	defer xioutil.SafeClose(updates)

	ctx, cancel := context.WithCancel(ctx)
	defer cancel()

     * build a smaller set of projects but perform other operations in the context of your reactor.
     */
    private List<MavenProject> allProjects;

    private MavenProject topLevelProject;

    private ProjectDependencyGraph projectDependencyGraph;

    private boolean parallel;

    /**
     * Plugin context keyed by project ({@link MavenProject#getId()}) and by plugin lookup key

例如，<a href="https://docs.python.org/zh-cn/3/tutorial/inputoutput.html#reading-and-writing-files" class="external-link" target="_blank">你可以使用`with`读取文件</a>：

```Python
with open("./somefile.txt") as f:
    contents = f.read()
    print(contents)
```

在底层，`open("./somefile.txt")`创建了一个被称为"上下文管理器"的对象。

当 `with` 代码块结束时，它会确保关闭文件，即使发生了异常也是如此。

当你使用 `yield` 创建一个依赖项时，**FastAPI** 会在内部将其转换为上下文管理器，并与其他相关工具结合使用。

   * safely be included in an XML document as element content. See section <a
   * href="http://www.w3.org/TR/2008/REC-xml-20081126/#syntax">2.4</a> of the XML specification.
   *
   * <p><b>Note:</b> Double and single quotes are not escaped, so it is <b>not safe</b> to use this
   * escaper to escape attribute values. Use {@link #xmlContentEscaper} if the output can appear in
   * element content or {@link #xmlAttributeEscaper} in attribute values.
   *

	}
}

func initConfigSubsystem(ctx context.Context, newObject ObjectLayer) error {
	// %w is used by all error returns here to make sure
	// we wrap the underlying error, make sure when you
	// are modifying this code that you do so, if and when
	// you want to add extra context to your error. This
	// ensures top level retry works accordingly.

	// Initialize config system.