import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Nonnull;

/**
 * A listener for session events.
 * TODO: open this to other events like similar to {@code org.apache.maven.eventspy.EventSpy}
 *
 * @since 4.0.0
 */
@Experimental
@FunctionalInterface
@Consumer
public interface Listener {
    void onEvent(@Nonnull Event event);

        for (MojoExecutionListener listener : listeners) {
            listener.afterExecutionFailure(event);
        }
    }

    public void addMojoExecutionListener(MojoExecutionListener listener) {
        this.listeners.add(listener);
    }

    public void removeMojoExecutionListener(MojoExecutionListener listener) {
        this.listeners.remove(listener);
    }

        for (MojoExecutionListener listener : listeners) {
            listener.beforeMojoExecution(event);
        }
    }

    public void afterMojoExecutionSuccess(MojoExecutionEvent event) throws MojoExecutionException {
        for (MojoExecutionListener listener : listeners) {
            listener.afterMojoExecutionSuccess(event);
        }
    }

    }

    public ExecutionListener chainListener(ExecutionListener listener) {
        if (eventSpies.isEmpty()) {
            return listener;
        }
        return new EventSpyExecutionListener(this, listener);
    }

    public RepositoryListener chainListener(RepositoryListener listener) {
        if (eventSpies.isEmpty()) {
            return listener;
        }
        return new EventSpyRepositoryListener(this, listener);

import org.apache.maven.plugin.descriptor.MojoDescriptor;
import org.apache.maven.plugin.descriptor.Parameter;
import org.codehaus.plexus.component.configurator.ConfigurationListener;

/**
 * A configuration listener to help validate the plugin configuration. For instance, check for required but missing
 * parameters.
 *
 */
class ValidatingConfigurationListener implements ConfigurationListener {
    private final Object mojo;

import org.apache.maven.api.annotations.Experimental;
import org.apache.maven.api.annotations.Nonnull;

/**
 * Event sent by maven during various phases of the build process.
 * Such events can be listened to using {@link Listener}s objects
 * registered in the {@link Session}.
 *
 * @since 4.0.0
 */
@Experimental
public interface Event {

    /**
     * Gets the type of the event.
     *

    private final ArtifactTransferListener listener;

    private final Map<Resource, ArtifactTransferResource> artifacts;

    private final Map<Resource, Long> transfers;

    public static TransferListener newAdapter(ArtifactTransferListener listener) {
        if (listener == null) {
            return null;
        } else {
            return new TransferListenerAdapter(listener);
        }
    }

                final ExpressionEvaluator evaluator,
                final ConfigurationListener listener)
                throws ComponentConfigurationException {
            final Object result =
                    super.fromConfiguration(lookup, configuration, type, enclosingType, loader, evaluator, listener);

            return result instanceof Path

                    listener.sessionStarted(event);
                    break;
                case SessionEnded:
                    listener.sessionEnded(event);
                    break;

                case ProjectSkipped:
                    listener.projectSkipped(event);
                    break;
                case ProjectStarted:
                    listener.projectStarted(event);
                    break;

        for (ProjectExecutionListener listener : listeners) {
            listener.beforeProjectExecution(event);
        }
    }

    public void beforeProjectLifecycleExecution(ProjectExecutionEvent event) throws LifecycleExecutionException {
        for (ProjectExecutionListener listener : listeners) {
            listener.beforeProjectLifecycleExecution(event);
        }
    }