@Nullable
    Object getInputLocation();

    default XmlNode merge(@Nullable XmlNode source) {
        return merge(source, (Boolean) null);
    }

    XmlNode merge(@Nullable XmlNode source, @Nullable Boolean childMergeOverride);

    /**
     * Merge recessive into dominant and return either {@code dominant}
     * with merged information or a clone of {@code recessive} if
     * {@code dominant} is {@code null}.

        }

        return new InputLocation(-1, -1, InputSource.merge(source.getSource(), target.getSource()), locations);
    } // -- InputLocation merge( InputLocation, InputLocation, boolean )

    /**
     * Merges the {@code source} location into the {@code target} location.
     * This method is used when the locations refer to lists and also merges the indices.
     *
     * @param target the target location

        Settings recessive = Settings.newBuilder()
                .pluginGroups(Arrays.asList("org.codehaus.plexus"))
                .build();

        Settings merged = SettingsUtilsV4.merge(dominant, recessive);

        List<String> pluginGroups = merged.getPluginGroups();

        assertNotNull(pluginGroups);
        assertEquals(3, pluginGroups.size());
        assertEquals("org.apache.maven.plugins", pluginGroups.get(0));

        throw new UnsupportedOperationException();
    }

    public static List<Plugin> orderAfterMerge(
            List<Plugin> merged, List<Plugin> highPrioritySource, List<Plugin> lowPrioritySource) {
        throw new UnsupportedOperationException();
    }

    <version>0.1</version>
  </parent>

  <artifactId>child</artifactId>

  <name>Maven Integration Test :: MNG-3938</name>
  <description>
    Test that plugin executions with the same id are merged during inheritance, especially executions using the
    default id, regardless whether the id is given explicitly by the user or implicitly assumed from defaults.
  </description>

  <build>
    <plugins>
      <plugin>

    // For a given project packaging find all the plugins that are bound to any registered
    // lifecycles. The project builder needs to now what default plugin information needs to be
    // merged into POM being built. Once the POM builder has this plugin information, versions can be assigned
    // by the POM builder because they will have to be defined in plugin management. Once this is setComplete then it

<project>
    <modelVersion>4.0.0</modelVersion>
    <groupId>tests.project</groupId>
    <artifactId>duplicate-plugin-defs-merged</artifactId>
    <version>1</version>

    <build>
      <plugins>
        <plugin>
          <artifactId>maven-compiler-plugin</artifactId>
          <dependencies>
            <dependency>
              <groupId>group</groupId>
              <artifactId>first</artifactId>
              <version>1</version>

        if (repositories != null) {
            Map<String, Server> serversById = new HashMap<>();

            if (servers != null) {
                for (Server server : servers) {
                    if (!serversById.containsKey(server.getId())) {
                        serversById.put(server.getId(), server);
                    }
                }

@return <code>true</code> if <var>item</var> matches, otherwise <code>false</code>. * * @see BaseMatcher */ boolean matches(Object item); /** * Generate a description of why the matcher has not accepted the item. * The description will be part of a larger description of why a matching * failed, so it should be concise. * This method assumes that <code>matches(item)</code> is false, but * will not check this. * * @param item The item that the Matcher has rejected. * @param mismatchDescription * The...

import org.apache.maven.api.services.model.*;

/**
 * Handles normalization of a model.
 *
 */
@Named
@Singleton
public class DefaultModelNormalizer implements ModelNormalizer {

    private DuplicateMerger merger = new DuplicateMerger();

    @Override
    public Model mergeDuplicates(Model model, ModelBuilderRequest request, ModelProblemCollector problems) {
        Model.Builder builder = Model.newBuilder(model);