You can add more than one event handler function.

And your application won't start receiving requests until all the `startup` event handlers have completed.

### `shutdown` event

To add a function that should be run when the application is shutting down, declare it with the event `"shutdown"`:

{* ../../docs_src/events/tutorial002.py hl[6] *}

    void projectDiscoveryStarted(ExecutionEvent event);

    void sessionStarted(ExecutionEvent event);

    void sessionEnded(ExecutionEvent event);

    void projectSkipped(ExecutionEvent event);

    void projectStarted(ExecutionEvent event);

    void projectSucceeded(ExecutionEvent event);

    void projectFailed(ExecutionEvent event);

    void mojoSkipped(ExecutionEvent event);

        }

        ArtifactTransferEvent event = wrap(transferEvent);
        event.setDataBuffer(buffer);
        event.setDataOffset(0);
        event.setDataLength(length);
        event.setTransferredBytes(transferred);

        listener.transferProgress(event);
    }

    public void transferStarted(TransferEvent transferEvent) {

 * events fired during collection.
 *
 * @since 3.9.0
 */
class ReverseTreeRepositoryListener extends AbstractRepositoryListener {
    @Override
    public void artifactResolved(RepositoryEvent event) {
        requireNonNull(event, "event cannot be null");

        if (!isLocalRepositoryArtifactOrMissing(event.getSession(), event.getArtifact())) {
            return;
        }

        dispatcher.onEvent(event);
        delegate.artifactInstalling(event);
    }

    @Override
    public void artifactResolved(RepositoryEvent event) {
        dispatcher.onEvent(event);
        delegate.artifactResolved(event);
    }

    @Override
    public void artifactResolving(RepositoryEvent event) {
        dispatcher.onEvent(event);
        delegate.artifactResolving(event);
    }

    @Override

     * @param event The event to fire, must not be {@code null}.
     */
    void fire(ModelBuildingListener listener, ModelBuildingEvent event);

    ModelBuildingEventCatapult BUILD_EXTENSIONS_ASSEMBLED = ModelBuildingListener::buildExtensionsAssembled;

    }

    @Override
    public void projectSkipped(ExecutionEvent event) {
        dispatcher.onEvent(event);
        delegate.projectSkipped(event);
    }

    @Override
    public void projectStarted(ExecutionEvent event) {
        dispatcher.onEvent(event);
        delegate.projectStarted(event);
    }

    @Override
    public void projectSucceeded(ExecutionEvent event) {
        dispatcher.onEvent(event);

    /**
     * Notifies the listener that the model has been constructed to the extent where build extensions can be processed.
     *
     * @param event The details about the event.
     */
    void buildExtensionsAssembled(ModelBuildingEvent event);

        ForkedProjectStarted,
        ForkedProjectSucceeded,
        ForkedProjectFailed,
    }

    /**
     * Gets the type of the event.
     *
     * @return The type of the event, never {@code null}.
     */
    Type getType();

    /**
     * Gets the session from which this event originates.
     *
     * @return The current session, never {@code null}.
     */
    MavenSession getSession();

    /**

        ongoing.remove(new TransferResourceIdentifier(event.getResource()));
        put(event, ongoing.isEmpty());
    }

    private static class Exchange {
        private final TransferEvent event;

        private Exchange(TransferEvent event) {
            this.event = event;
        }

        public void process(Consumer<TransferEvent> consumer) {
            consumer.accept(event);
        }