return;
            }

            if (event.getArtifact() != null) {
                trackingData.add(indent + event.getArtifact());
                indent += "  ";
            }
            trackingData.add(indent + plugin.getGroupId() + ":" + plugin.getArtifactId() + ":" + plugin.getVersion());
            indent += "  ";

            InputLocation location = plugin.getLocation("");

/**
 * Registry of subscribers to a single event bus.
 *
 * @author Colin Decker
 */
@ElementTypesAreNonnullByDefault
final class SubscriberRegistry {

  /**
   * All registered subscribers, indexed by event type.
   *
   * <p>The {@link CopyOnWriteArraySet} values make it easy and relatively lightweight to get an
   * immutable snapshot of all current subscribers to an event without any locking.
   */

### `startup` event

To add a function that should be run before the application starts, declare it with the event `"startup"`:

{* ../../docs_src/events/tutorial001.py hl[8] *}

In this case, the `startup` event handler function will initialize the items "database" (just a `dict`) with some values.

You can add more than one event handler function.

func applyExpiryRule(event lifecycle.Event, src lcEventSrc, obj ObjectInfo) bool {
	globalExpiryState.enqueueByDays(obj, event, src)
	return true
}

// Perform actions (removal or transitioning of objects), return true the action is successfully performed
func applyLifecycleAction(event lifecycle.Event, src lcEventSrc, obj ObjectInfo) (success bool) {
	switch action := event.Action; action {

     * The mojo started event is also captured to determine the lifecycle
     * phases the project has been through.
     *
     * @param event the execution event
     */
    private void processEvent(ExecutionEvent event) {
        MavenProject project = event.getProject();
        switch (event.getType()) {
            case MojoStarted:
                String phase = event.getMojoExecution().getLifecyclePhase();

Diese Funktionen können mit `async def` oder normalem `def` deklariert werden.

### `startup`-Event

Um eine Funktion hinzuzufügen, die vor dem Start der Anwendung ausgeführt werden soll, deklarieren Sie diese mit dem Event `startup`:

```Python hl_lines="8"
{!../../docs_src/events/tutorial001.py!}
```

                    // last ANSI escape code is reset: no next color
                    nextColor = "";
                }
            }

            // effective line, with indent and reset if end is colored
            line = indent + line + ("".equals(nextColor) ? "" : ANSI_RESET);

            if ((i == lines.length - 1)
                    && (context.invokerRequest.options().showErrors().orElse(false)

        indent = indent.substring(2);
    }

    public void includeArtifact(Artifact artifact) {
        logger.debug(indent + artifact + " (selected for " + artifact.getScope() + ")");
    }

    public void omitForNearer(Artifact omitted, Artifact kept) {
        String omittedVersion = omitted.getVersion();
        String keptVersion = kept.getVersion();

        if (!Objects.equals(omittedVersion, keptVersion)) {

    }

    @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);

    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);