### Async Context Manager { #async-context-manager }

If you check, the function is decorated with an `@asynccontextmanager`.

That converts the function into something called an "**async context manager**".

{* ../../docs_src/events/tutorial003_py310.py hl[1,13] *}

	}

	if optimizer, ok := stmt.Dest.(StatementModifier); ok {
		optimizer.ModifyStatement(stmt)
	}

	if db.DefaultContextTimeout > 0 {
		if _, ok := stmt.Context.Deadline(); !ok {
			stmt.Context, _ = context.WithTimeout(stmt.Context, db.DefaultContextTimeout)
		}
	}

	// assign model values
	if stmt.Model == nil {
		stmt.Model = stmt.Dest
	} else if stmt.Dest == nil {
		stmt.Dest = stmt.Model

    public List<CoreExtension> selectCoreExtensions(LookupInvoker<C> invoker, C context) {
        Optional<List<CoreExtensions>> coreExtensions = context.invokerRequest.coreExtensions();
        if (coreExtensions.isEmpty() || coreExtensions.get().isEmpty()) {
            return List.of();
        }

        return selectCoreExtensions(
                context, context.invokerRequest.coreExtensions().orElseThrow());
    }

    /**

	}
	if len(extKey) != 32 { // safety check
		logger.CriticalIf(context.Background(), errors.New("crypto: invalid key length"))
	}
	var nonce [32]byte
	if _, err := io.ReadFull(random, nonce[:]); err != nil {
		logger.CriticalIf(context.Background(), errOutOfEntropy)
	}

	const Context = "object-encryption-key generation"
	mac := hmac.New(sha256.New, extKey)
	mac.Write([]byte(Context))
	mac.Write(nonce[:])
	mac.Sum(key[:0])
	return key

// DialContext is a function to make custom Dial for internode communications
type DialContext func(ctx context.Context, network, address string) (net.Conn, error)

// NewInternodeDialContext configures a custom dialer for internode communications
func NewInternodeDialContext(dialTimeout time.Duration, _ TCPOptions) DialContext {
	return func(ctx context.Context, network, addr string) (net.Conn, error) {
		dialer := &net.Dialer{
			Timeout: dialTimeout,
		}

    }

    private void addTOC(Document document) {
        Element tocSection = document.body().select("section.topic").first().before("<section class='table-of-contents'/>").previousElementSibling();
        tocSection.append("<h2>Table Of Contents</h2>");
        Element toc = tocSection.append("<ul class='toc'/>").children().last();

        Elements h23elements = document.select("h2,h3");

    @Override
    public int size() {
        // Context header (16) + name length (4) + padding to 8-byte alignment + data (16)
        return 16 + 4 + 4 + STRUCTURE_SIZE;
    }

    @Override
    public int encode(byte[] dst, int dstIndex) {
        int start = dstIndex;

        // Write context header
        SMBUtil.writeInt4(0, dst, dstIndex); // Next (offset to next context, 0 for last)
        dstIndex += 4;

			for i := 0; i < stmt.ReflectValue.Len(); i++ {
				if stmt.ReflectValue.CanAddr() {
					field.Set(stmt.Context, stmt.ReflectValue.Index(i), value)
				}
			}
		}
	case reflect.Struct:
		assignValue = func(field *schema.Field, value interface{}) {
			if stmt.ReflectValue.CanAddr() {
				field.Set(stmt.Context, stmt.ReflectValue, value)
			}
		}
	default:
		assignValue = func(field *schema.Field, value interface{}) {

     *
     * @param projectDirectory The base directory of the current project, may be {@code null} if profile activation
     *                         happens in the context of metadata retrieval rather than project building.
     * @return This context, never {@code null}.
     */
    public DefaultProfileActivationContext setProjectDirectory(File projectDirectory) {
        this.projectDirectory = projectDirectory;

			},
			nil, nil,
		},
		// Checks if wrapped context cancellation errors are grouped as one.
		{canceledErrs, nil, context.Canceled},
	}
	// Validates list of all the testcases for returning valid errors.
	for i, testCase := range testCases {
		gotErr := reduceReadQuorumErrs(t.Context(), testCase.errs, testCase.ignoredErrs, 5)
		if gotErr != testCase.err {