*/
    @Nullable
    public static XmlNode merge(XmlNode dominant, XmlNode recessive) {
        return merge(dominant, recessive, null);
    }

    /**
     * Merges two XML nodes.
     */
    @Nullable
    public static XmlNode merge(
            @Nullable XmlNode dominant, @Nullable XmlNode recessive, @Nullable Boolean childMergeOverride) {

        this.callback = callback;
    }

    @Override
    public void configure(Binder binder) {
        if (extension.getKey() != null) {
            XmlNode configuration = extension.getConfiguration();
            if (configuration == null) {
                configuration = XmlNode.newInstance("configuration");
            }
            UnaryOperator<String> cb = Interpolator.memoize(callback);

        this.callback = callback;
    }

    @Override
    public void configure(Binder binder) {
        if (extension.getKey() != null) {
            XmlNode configuration = extension.getConfiguration();
            if (configuration == null) {
                configuration = XmlNode.newInstance("configuration");
            }
            UnaryOperator<String> cb = Interpolator.memoize(callback);

    private final Set<String> packages;

    private final String key;

    private final XmlNode configuration;

    public CoreExtensionEntry(
            ClassRealm realm,
            Collection<String> artifacts,
            Collection<String> packages,
            String key,
            XmlNode configuration) {
        this.realm = realm;

            XmlNode pomConfiguration = null;

            if (pluginExecution != null) {
                pomConfiguration = pluginExecution.getDelegate().getConfiguration();
            } else if (allowPluginLevelConfig) {
                pomConfiguration = plugin.getDelegate().getConfiguration();
            }

            XmlNode mojoConfiguration = mojoExecution.getConfiguration() != null

                throw new ComponentConfigurationException("Unable to convert configuration to xml node", e);
            }
        }

        XmlNode toXml(PlexusConfiguration config, ExpressionEvaluator evaluator) throws ExpressionEvaluationException {
            List<XmlNode> children = new ArrayList<>();
            for (PlexusConfiguration c : config.getChildren()) {
                children.add(toXml(c, evaluator));
            }

package org.apache.maven.lifecycle.mapping;

import java.util.List;

import org.apache.maven.api.xml.XmlNode;
import org.apache.maven.model.Dependency;

/**
 * Mojo (plugin goal) binding to a lifecycle phase.
 *
 * @see LifecyclePhase
 */
public class LifecycleMojo {

    private String goal;
    private XmlNode configuration;
    private List<Dependency> dependencies;

    public String getGoal() {

                }
            }
        }
        return null;
    }

    private static String mayGetChild(XmlNode node, String child) {
        XmlNode c = node.child(child);
        if (c != null) {
            return c.value();
        }
        return null;
    }

import org.apache.maven.api.plugin.descriptor.MojoDescriptor;
import org.apache.maven.api.plugin.descriptor.PluginDescriptor;
import org.apache.maven.api.plugin.descriptor.lifecycle.Lifecycle;
import org.apache.maven.api.xml.XmlNode;
import org.apache.maven.impl.DefaultNode;
import org.codehaus.plexus.util.xml.Xpp3Dom;
import org.eclipse.aether.graph.DependencyNode;

public class DefaultMojoExecution implements MojoExecution {

        Plugin plugin = model.getBuild().getPlugins().get(0);
        XmlNode node = plugin.getConfiguration();
        assertNotNull(node);
        assertEquals("http://maven.apache.org/POM/4.0.0", node.namespaceUri());
        assertEquals("m", node.prefix());
        assertEquals("configuration", node.name());
        assertEquals(1, node.children().size());
        XmlNode myConfig = node.children().get(0);