### Async Context Manager { #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_py39.py hl[1,13] *}

    protected String parseCharset(final String content) {
        final Pattern pattern = Pattern.compile("; *charset *= *([a-zA-Z0-9\\-_]+)", Pattern.CASE_INSENSITIVE);
        final Matcher matcher = pattern.matcher(content);
        if (matcher.find()) {
            return matcher.group(1);
        }
        return null;
    }

    /**
     * Gets a duplicate URL by adding or removing a trailing slash.
     *

   * https://cs.android.com/android/platform/superproject/+/android-2.3.7_r1:libcore/luni/src/main/java/java/util/regex/Matcher.java;l=550;drc=5850271b4ab93ebc27c1d49169a348c6be3c7f04
   */
  private static MatchResult createMatchResult() {
    Matcher matcher = Pattern.compile(".").matcher("X");
    matcher.find();
    return matcher.toMatchResult();
  }

  private static final ClassToInstanceMap<Object> DEFAULTS =

     * @param value The value to trim.
     * @return The trimmed value.
     */
    protected String trimSpace(final String value) {
        if (trimSpaceEnabled) {
            final Matcher matcher = SPACE_PATTERN.matcher(value);
            return matcher.replaceAll(" ").trim();
        }
        return value;
    }

    /**
     * Adds a field rule to the transformer.
     * @param name The name of the field.

            client.setMaxRetryCount(5);
            client.setRetryInterval(500);
        }).prototype("fsClient", FileSystemClient.class).prototype("ruleManager", RuleManagerImpl.class, manager -> {
            manager.addRule(container.getComponent("sitemapsRule"));
            manager.addRule(container.getComponent("fileRule"));
        })
                .prototype("accessResult", AccessResultImpl.class)
                .prototype("urlQueue", UrlQueueImpl.class)

    }

    /**
     * Gets the message manager component.
     * @return The message manager.
     */
    public static MessageManager getMessageManager() {
        return getComponent(MESSAGE_MANAGER);
    }

    /**
     * Gets the dictionary manager component.
     * @return The dictionary manager.
     */
    public static DictionaryManager getDictionaryManager() {

    assertTrue(toTest, toTest.matches(".*\\{field1\\=Hello\\}"));
  }

  public void testToStringLenient_oneIntegerField() {
    String toTest =
        MoreObjects.toStringHelper(new TestClass()).add("field1", Integer.valueOf(42)).toString();
    assertTrue(toTest, toTest.matches(".*\\{field1\\=42\\}"));
  }

  public void testToStringLenient_nullInteger() {

### 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_py39.py hl[1,13] *}

    private final ConcurrentHashMap<String, Type> usedTypes;

    private final LegacyArtifactHandlerManager manager;

    @Inject
    public DefaultTypeRegistry(Lookup lookup, LanguageRegistry languageRegistry, LegacyArtifactHandlerManager manager) {
        this.lookup = requireNonNull(lookup, "lookup cannot be null");

	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