modelMerger.mergeContributor_Roles( target, source, true, null );

        assertThat( target.getRoles(), contains( "first", "second", "third" ) );
    }

    @Test
    public void mergeUrl()
    {
        Model target = new Model();
        target.setUrl( "TARGET" );;

        Model source = new Model();
        source.setUrl( "SOURCE" );

class MavenToolchainMergerTest {
    private MavenToolchainMerger merger = new MavenToolchainMerger();

    private DefaultToolchainsReader reader = new DefaultToolchainsReader();

    @Test
    void testMergeNulls() {
        merger.merge(null, null, null);

        PersistedToolchains pt = new PersistedToolchains();
        merger.merge(pt, null, null);
        merger.merge(null, pt, null);
    }

    @Test

                Model.Builder builder = Model.newBuilder(model);
                merger.mergeModelBase(builder, model, profile);

                if (profile.getBuild() != null) {
                    Build build = model.getBuild() != null ? model.getBuild() : Build.newInstance();
                    Build.Builder bbuilder = Build.newBuilder(build);
                    merger.mergeBuildBase(bbuilder, build, profile.getBuild());

 */
@Named
@Singleton
@Deprecated(since = "4.0.0")
public class DefaultModelNormalizer implements ModelNormalizer {

    private DuplicateMerger merger = new DuplicateMerger();

    @Override
    public void mergeDuplicates(
            org.apache.maven.model.Model model, ModelBuildingRequest request, ModelProblemCollector problems) {

    private ManagementModelMerger merger = new ManagementModelMerger();

    @Override
    public void injectManagement(
            org.apache.maven.model.Model model, ModelBuildingRequest request, ModelProblemCollector problems) {
        model.update(merger.mergeManagedDependencies(model.getDelegate()));
    }

    /**
     * ManagementModelMerger
     */

 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.maven.model.merge;

import java.util.Map;
import java.util.Objects;

/**
 * The domain-specific model merger for the Maven POM, overriding generic code from parent class when necessary with
 * more adapted algorithms.
 *
 * @deprecated use {@link org.apache.maven.internal.impl.model.MavenModelMerger} instead
 */

    private static final String CHILD_DIRECTORY = "child-directory";

    private static final String CHILD_DIRECTORY_PROPERTY = "project.directory";

    private final InheritanceModelMerger merger = new InheritanceModelMerger();

    @Override
    public Model assembleModelInheritance(
            Model child, Model parent, ModelBuildingRequest request, ModelProblemCollector problems) {

// CHECKSTYLE_OFF: RegexpHeader
/**
 * POM merger.
 */

public class DefaultPluginManagementInjector implements PluginManagementInjector {

    private ManagementModelMerger merger = new ManagementModelMerger();

    @Override
    public void injectManagement(
            org.apache.maven.model.Model model, ModelBuildingRequest request, ModelProblemCollector problems) {
        model.update(merger.mergeManagedBuildPlugins(model.getDelegate()));
    }

    /**
     * ManagementModelMerger
     */

 The following are generated from this model:

   * {{{./apidocs/index.html}Java sources}} with Reader and Writers for the Xpp3 XML parser, <<<ToAPiV3()>>> and <<<ToApiV4()>>> transformers, and <<<v4>>> package
     for Merger and v4 Reader and Writers for the Xpp3 XML parser,

   * A {{{./toolchains.html}Descriptor Reference}}