// Don't need to interrupt thread since we never start it in tests
            }
        };
        manager.init();
        assertTrue(manager.baseDir.exists());
        manager.destroy();
    }

    // Test initialization failure
    public void test_init_failure() {
        ThumbnailManager manager = new ThumbnailManager() {
            @Override
            public void init() {

### 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.py hl[1,13] *}

    private final ChannelManager manager;
    private final ExecutorService executor;
    private final ConcurrentMap<String, FailoverState> failoverStates;

    /**
     * Create channel failover handler
     *
     * @param manager channel manager
     */
    public ChannelFailover(ChannelManager manager) {
        this.manager = manager;
        this.executor = Executors.newCachedThreadPool(r -> {

            public String getQueryBrowserLangParameterName() {
                return "lang";
            }
        };
        ComponentUtil.setFessConfig(mockConfig);

        // Setup mock request manager
        RequestManager mockRequestManager = createMockRequestManager("en_US");

        // Execute
        OptionalThing<Locale> result = provider.findBusinessLocale(null, mockRequestManager);

        // Verify

		*GetUser("delete_slice_with_associations2", Config{Account: true, Pets: 3, Toys: 2, Company: true, Manager: true, Team: 2, Languages: 2, Friends: 3}),
		*GetUser("delete_slice_with_associations3", Config{Account: true, Pets: 2, Toys: 3, Company: true, Manager: true, Team: 3, Languages: 3, Friends: 2}),

        private final String resourceId;
        private final ResourceManager manager;
        private volatile boolean closed = false;

        ManagedResource(T resource, String resourceId, ResourceManager manager) {
            this.resource = resource;
            this.resourceId = resourceId;
            this.manager = manager;
        }

        public T get() {
            if (closed) {

import jcifs.internal.smb2.ioctl.QueryNetworkInterfaceInfoResponse;
import jcifs.internal.smb2.ioctl.Smb2IoctlRequest;
import jcifs.internal.smb2.session.Smb2SessionSetupRequest;

/**
 * Manages SMB3 Multi-Channel connections
 */
public class ChannelManager {

    private static final Logger log = LoggerFactory.getLogger(ChannelManager.class);

    private final CIFSContext context;

### Async Context Manager

Si revisas, la función está decorada con un `@asynccontextmanager`.

Eso convierte a la función en algo llamado un "**async context manager**".

{* ../../docs_src/events/tutorial003.py hl[1,13] *}

Un **context manager** en Python es algo que puedes usar en una declaración `with`, por ejemplo, `open()` puede ser usado como un context manager:

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

	result.Company = user2.Company
	result.Manager = user2.Manager
	result.Team = user2.Team
	result.Languages = user2.Languages
	result.Friends = user2.Friends

	DB.Select("Name", "Account", "Toys", "Manager", "ManagerID", "Languages").Save(&result)

	var result2 User

* ✨ Add support for `lifespan` async context managers (superseding `startup` and `shutdown` events). Initial PR [#2944](https://github.com/tiangolo/fastapi/pull/2944) by [@uSpike](https://github.com/uSpike).

Now, instead of using independent `startup` and `shutdown` events, you can define that logic in a single function with `yield` decorated with `@asynccontextmanager` (an async context manager).

For example:

```Python