* ✨ 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

import org.eclipse.aether.resolution.ArtifactDescriptorPolicy;
import org.eclipse.aether.util.artifact.DefaultArtifactTypeRegistry;
import org.eclipse.aether.util.graph.manager.ClassicDependencyManager;
import org.eclipse.aether.util.graph.manager.TransitiveDependencyManager;
import org.eclipse.aether.util.graph.selector.AndDependencySelector;
import org.eclipse.aether.util.graph.selector.ExclusionDependencySelector;

.29.2](https://console.cloud.google.com/gcr/images/k8s-artifacts-prod/us/kube-controller-manager) | [amd64](https://console.cloud.google.com/gcr/images/k8s-artifacts-prod/us/kube-controller-manager-amd64), [arm64](https://console.cloud.google.com/gcr/images/k8s-artifacts-prod/us/kube-controller-manager-arm64), [ppc64le](https://console.cloud.google.com/gcr/images/k8s-artifacts-prod/us/kube-controller-manager-ppc64le), [s390x](https://console.cloud.google.com/gcr/images/k8s-artifacts-prod/us/kube...

v1.25.16](https://console.cloud.google.com/gcr/images/k8s-artifacts-prod/us/kube-controller-manager) | [amd64](https://console.cloud.google.com/gcr/images/k8s-artifacts-prod/us/kube-controller-manager-amd64), [arm](https://console.cloud.google.com/gcr/images/k8s-artifacts-prod/us/kube-controller-manager-arm), [arm64](https://console.cloud.google.com/gcr/images/k8s-artifacts-prod/us/kube-controller-manager-arm64), [ppc64le](https://console.cloud.google.com/gcr/images/k8s-artifacts-prod/us/kube-co...

     * @return A new {@link StopwordsFile} associated with the dictionary manager.
     */
    @Override
    protected DictionaryFile<? extends DictionaryItem> newDictionaryFile(final String id, final String path, final Date timestamp) {
        return new StopwordsFile(id, path, timestamp).manager(dictionaryManager);
    }

    public Date getTimestamp() {
        return timestamp;
    }

    /**
     * Sets the dictionary manager for this file and returns this instance.
     *
     * @param dictionaryManager the dictionary manager to set
     * @return this dictionary file instance for method chaining
     */
    public DictionaryFile<T> manager(final DictionaryManager dictionaryManager) {
        this.dictionaryManager = dictionaryManager;

        this.urlFilter = urlFilter;
    }

    /**
     * Returns the rule manager.
     * @return The RuleManager.
     */
    public RuleManager getRuleManager() {
        return ruleManager;
    }

    /**
     * Sets the rule manager.
     * @param ruleManager The RuleManager.
     */
    public void setRuleManager(final RuleManager ruleManager) {

4](https://console.cloud.google.com/artifacts/docker/k8s-artifacts-prod/southamerica-east1/images/kube-controller-manager) | [amd64](https://console.cloud.google.com/artifacts/docker/k8s-artifacts-prod/southamerica-east1/images/kube-controller-manager-amd64), [arm64](https://console.cloud.google.com/artifacts/docker/k8s-artifacts-prod/southamerica-east1/images/kube-controller-manager-arm64), [ppc64le](https://console.cloud.google.com/artifacts/docker/k8s-artifacts-prod/southamerica-east1/images/...

     * Constructs a new CharMappingCreator with the mapping file pattern.
     */
    public CharMappingCreator() {
        super("mapping.*\\.txt");
    }

    /**
     * Registers this creator with the dictionary manager after construction.
     */
    @PostConstruct
    public void register() {
        if (logger.isInfoEnabled()) {
            logger.info("Loaded {}", this.getClass().getSimpleName());
        }

    /**
     * Constructs a new Kuromoji creator.
     */
    public KuromojiCreator() {
        super("kuromoji.*\\.txt");
    }

    /**
     * Registers this creator to the dictionary manager.
     */
    @PostConstruct
    public void register() {
        if (logger.isInfoEnabled()) {
            logger.info("Loaded {}", this.getClass().getSimpleName());
        }