}
                }
                // Children
                for (int i = 0, l = dom.getChildCount(); i < l; i++) {
                    visit(dom.getChild(i));
                }
            }
        }

        private void visit(Extension extension) {
            if (extension != null) {
                String org, val;
                // GroupId

            if (!parameter.isRequired()) {
                continue;
            }

            Object value = null;

            PlexusConfiguration config = configuration.getChild(parameter.getName(), false);
            if (config != null) {
                String expression = config.getValue(null);

                try {
                    value = expressionEvaluator.evaluate(expression);

void Xpp3Dom(Xpp3Dom); public String getName(); public String getValue(); public void setValue(String); public String[] getAttributeNames(); public String getAttribute(String); public void setAttribute(String, String); public Xpp3Dom getChild(int); public Xpp3Dom getChild(String); public void addChild(Xpp3Dom); public Xpp3Dom[] getChildren(); public Xpp3Dom[] getChildren(String); public int getChildCount(); public void removeChild(int); public Xpp3Dom getParent(); public void setParent(Xpp3Dom); public...

            if (target.getBuild() == null) {
                target.setBuild(new Build());
            }

            Map<Object, Object> context = Collections.singletonMap(
                    PLUGIN_MANAGEMENT, target.getBuild().getPluginManagement());

            mergePluginContainer_Plugins(target.getBuild(), source.getBuild(), false, context);
        }

        projects.add(pluginProjectA);
        pluginProjectA.getModel().getBuild().addPlugin(createPlugin("group", "plugin-b", "1.0"));

        MavenProject pluginProjectB = createProject("group", "plugin-b", "2.0-SNAPSHOT");
        projects.add(pluginProjectB);
        pluginProjectB.getModel().getBuild().addPlugin(createPlugin("group", "plugin-a", "1.0"));

        if (profile != null) {
            merger.mergeModelBase(model, profile);

            if (profile.getBuild() != null) {
                if (model.getBuild() == null) {
                    model.setBuild(new Build());
                }
                merger.mergeBuildBase(model.getBuild(), profile.getBuild());
            }
        }
    }

    /**
     * ProfileModelMerger
     */

        Properties properties =
                loadResumptionFile(Paths.get(rootProject.getBuild().getDirectory()));
        applyResumptionProperties(request, properties);
    }

    @Override
    public void removeResumptionData(MavenProject rootProject) {
        Path resumeProperties = Paths.get(rootProject.getBuild().getDirectory(), RESUME_PROPERTIES_FILENAME);
        try {
            Files.deleteIfExists(resumeProperties);

        build.setOutputDirectory("myOutputDirectory");
        model.setBuild(build);
        Build build2 = model.getBuild();
        assertNotNull(build2);
        assertEquals("myOutputDirectory", build2.getOutputDirectory());
        model.setBuild(null);
        assertNull(model.getBuild());
    }

    @Test
    void testEqualsNullSafe() {
        assertNotEquals(null, new Model());

            model = new MavenXpp3Reader().read(is);
        }

        // Serialize an inner child here so that the BaseObject.childrenTracking is non null
        Build build = model.getBuild();

        ByteArrayOutputStream baos = new ByteArrayOutputStream();
        try (ObjectOutputStream oos = new ObjectOutputStream(baos)) {
            oos.writeObject(build);
        }

        Build build2;

    }

    public String getDefaultGoal() {
        return getBuild() != null ? getBuild().getDefaultGoal() : null;
    }

    public Plugin getPlugin(String pluginKey) {
        org.apache.maven.api.model.Plugin plugin =
                getBuild().getDelegate().getPluginsAsMap().get(pluginKey);
        return plugin != null ? new Plugin(plugin, getBuild()) : null;
    }

    /**
     * Default toString