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。

	if !s.checkID(opts.DiskID) {
		return nil, grid.NewRemoteErr(errDiskNotFound)
	}
	info, err := s.getStorage().DiskInfo(context.Background(), *opts)
	if err != nil {
		info.Error = err.Error()
	}
	return &info, nil
}

func (s *storageRESTServer) NSScannerHandler(ctx context.Context, params *nsScannerOptions, out chan<- *nsScannerResp) *grid.RemoteErr {
	if !s.checkID(params.DiskID) {

// IsRemote returns true if this object version's contents are in its remote
// tier.
func (fi FileInfo) IsRemote() bool {
	if fi.TransitionStatus != lifecycle.TransitionComplete {
		return false
	}
	return !isRestoredObjectOnDisk(fi.Metadata)
}

// IsRemote returns true if this object version's contents are in its remote
// tier.
func (oi ObjectInfo) IsRemote() bool {

## Conceitos de Implantação

Aqui você viu como usar vários **trabalhadores** para **paralelizar** a execução do aplicativo, aproveitar **vários núcleos** na CPU e conseguir atender **mais solicitações**.

    /**
     * @throws Exception
     */
    public void testGetContentsAsStream() throws Exception {
        final String contents = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><foo/>";
        assertNotNull("1", DomUtil.getContentsAsStream(contents, "UTF-8"));
    }

    /**
     * @throws Exception
     */
    public void testToString() throws Exception {

     */
    private void ensureRoomFor(int newElements) {
      @Nullable Object[] contents = this.contents;
      int newCapacity = expandedCapacity(contents.length, size + newElements);
      // expandedCapacity handles the overflow case
      if (newCapacity > contents.length || forceCopy) {
        this.contents = Arrays.copyOf(this.contents, newCapacity);
        forceCopy = false;
      }
    }

	return p, nil
}

func (iamOS *IAMObjectStore) loadPolicyDoc(ctx context.Context, policy string, m map[string]PolicyDoc) error {
	p, err := iamOS.loadPolicy(ctx, policy)
	if err != nil {
		return err
	}
	m[policy] = p
	return nil
}

func (iamOS *IAMObjectStore) loadPolicyDocs(ctx context.Context, m map[string]PolicyDoc) error {
	ctx, cancel := context.WithCancel(ctx)
	defer cancel()

    final Multiset<E> contents;

    /**
     * Creates a new builder. The returned builder is equivalent to the builder generated by {@link
     * ImmutableMultiset#builder}.
     */
    public Builder() {
      this(LinkedHashMultiset.<E>create());
    }

    Builder(Multiset<E> contents) {
      this.contents = contents;
    }

    /**

```Python
with open("file.txt") as file:
    file.read()
```

Nas versões mais recentes de Python, há também um **gerenciador de contexto assíncrono**. Você o usaria com `async with`:

```Python
async with lifespan(app):
    await do_stuff()
```

@NullUnmarked
public final class SetsFilterNavigableSetTest extends AbstractFilteredNavigableSetTest {
  @Override
  NavigableSet<Integer> createUnfiltered(Iterable<Integer> contents) {
    return Sets.newTreeSet(contents);
  }

  @Override
  NavigableSet<Integer> filter(
      NavigableSet<Integer> elements, Predicate<? super Integer> predicate) {
    return Sets.filter(elements, predicate);
  }