```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。

is specified via the `role_policy` configuration parameter or the `MINIO_IDENTITY_OPENID_ROLE_POLICY` environment variable. The value is a comma-separated list of IAM access policy names already defined in the server. In this situation, the server prints a role ARN at startup that must be specified as a `RoleArn` API request parameter in the STS AssumeRoleWithWebIdentity API call. When using Role Policies, multiple OpenID providers and/or client applications (with unique client IDs) may be configured...

	h.workers.Add(1)
	defer h.workers.Add(-1)

	h.wg.Add(1)
	defer h.wg.Done()

	entries := make([]interface{}, 0)
	name := h.Name()

	defer func() {
		// re-load the global buffer pointer
		// in case it was modified by a new target.
		logChLock.Lock()
		currentGlobalBuffer, ok := logChBuffers[name]
		logChLock.Unlock()
		if !ok {
			return
		}

		for _, v := range entries {

	token, err := MockOpenIDTestUserInteraction(ctx, testAppParams, "******@****.***", "dillon")
	if err != nil {
		c.Fatalf("mock user err: %v", err)
	}
	// fmt.Printf("TOKEN: %s\n", token)

	webID := cr.STSWebIdentity{
		Client:      s.TestSuiteCommon.client,
		STSEndpoint: s.endPoint,
		GetWebIDTokenExpiry: func() (*cr.WebIdentityToken, error) {

		return errDiskNotFound
	}
	return err
}

// Abstracts a remote disk.
type storageRESTClient struct {
	endpoint   Endpoint
	restClient *rest.Client
	gridConn   *grid.Subroute
	diskID     atomic.Pointer[string]

	diskInfoCache *cachevalue.Cache[DiskInfo]
}

// Retrieve location indexes.
func (client *storageRESTClient) GetDiskLoc() (poolIdx, setIdx, diskIdx int) {

   */
  protected final <T> void setDefault(Class<T> type, T value) {
    tester.setDefault(type, value);
  }

  /**
   * Sets two distinct values for {@code type}. These values can be used for both null pointer
   * testing and equals testing.
   *
   * @since 17.0
   */
  protected final <T> void setDistinctValues(Class<T> type, T value1, T value2) {
    tester.setDistinctValues(type, value1, value2);
  }

        if (result < 0L || result > Integer.MAX_VALUE || line.isNotEmpty()) {
          throw IOException("expected an int but was \"$result$line\"")
        }
        return result.toInt()
      } catch (e: NumberFormatException) {
        throw IOException(e.message)
      }
    }

    /**
     * Returns true if none of the Vary headers have changed between [cachedRequest] and

		size:          actualSize,
		offset:        0,
		reader:        nil,
	}
}

// Seek call to implement io.Seeker
func (rsc *ObjectReadSeekCloser) Seek(offset int64, whence int) (int64, error) {
	// fmt.Printf("actual: %v offset: %v (%v) whence: %v\n", rsc.size, offset, rsc.offset, whence)
	switch whence {
	case io.SeekStart:
		rsc.offset = offset
	case io.SeekCurrent:
		rsc.offset += offset
	case io.SeekEnd:

  private ExecutionSequencer() {}

  /** Creates a new instance. */
  public static ExecutionSequencer create() {
    return new ExecutionSequencer();
  }

  /** This reference acts as a pointer tracking the head of a linked list of ListenableFutures. */
  private final AtomicReference<ListenableFuture<@Nullable Void>> ref =
      new AtomicReference<>(immediateVoidFuture());

	}

	lockRetryBackOff = backoffWait(
		lockRetryMinInterval,
		100*time.Millisecond,
		5*time.Second,
	)
}

func log(format string, data ...interface{}) {
	if dsyncLog {
		console.Printf(format, data...)
	}
}

const (
	// dRWMutexAcquireTimeout - default tolerance limit to wait for lock acquisition before.
	drwMutexAcquireTimeout = 1 * time.Second // 1 second.