import org.apache.maven.api.services.ModelBuilderRequest;
import org.apache.maven.api.services.ModelProblemCollector;

/**
 * Holds data relevant for a model building event.
 *
 */
public interface ModelBuildingEvent {

    /**
     * Gets the model being built. The precise state of this model depends on the event being fired.
     *
     * @return The model being built, never {@code null}.
     */
    Model model();

 */
public interface ModelBuildingListener {

    /**
     * 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.
     */
    default void buildExtensionsAssembled(ModelBuildingEvent event) {}

import org.apache.maven.api.services.ModelProblemCollector;
import org.apache.maven.api.services.model.ModelBuildingEvent;

/**
 * Holds data relevant for a model building event.
 */
record DefaultModelBuildingEvent(
        Model model, Consumer<Model> update, ModelBuilderRequest request, ModelProblemCollector problems)

import java.util.List;
import java.util.Objects;

import org.apache.maven.api.services.BuilderProblem;
import org.apache.maven.api.services.ModelProblem;
import org.apache.maven.api.services.model.ModelBuildingEvent;
import org.apache.maven.api.services.model.ModelBuildingListener;
import org.apache.maven.artifact.repository.ArtifactRepository;
import org.apache.maven.model.Model;
import org.apache.maven.plugin.PluginManagerException;

            ModelProblemCollector problems,
            BiConsumer<ModelBuildingListener, ModelBuildingEvent> catapult) {
        ModelBuildingListener listener = getModelBuildingListener(request);

        if (listener != null) {
            AtomicReference<Model> m = new AtomicReference<>(model);

            ModelBuildingEvent event = new DefaultModelBuildingEvent(model, m::set, request, problems);