Model source = Model.newBuilder().artifactId("SOURCE").build();

        Model merged = mavenMerger.merge(target, source, true, null);
        assertThat(merged.getArtifactId(), is("SOURCE"));

        merged = mavenMerger.merge(target, source, false, null);
        assertThat(merged.getArtifactId(), is("TARGET"));
    }

    @Test
    void mergeSameContributors() {
        Contributor contributor =

        }

        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

 */
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.
 *
 */
public class MavenModelMerger extends org.apache.maven.internal.impl.model.MavenModelMerger {

    /**
     * Merges the specified source object into the given target object.

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

     * @param dominant The dominant DOM into which the recessive value/attributes/children will be merged
     * @param recessive The recessive DOM, which will be merged into the dominant DOM
     * @return merged DOM
     */
    public static XmlNode merge(XmlNode dominant, XmlNode recessive) {
        return merge(dominant, recessive, null);
    }

    // ----------------------------------------------------------------------

    }

    /**
     * Merges the {@code source} location into the {@code target} location.
     *
     * @param target the target location
     * @param source the source location
     * @param sourceDominant the boolean indicating of {@code source} is dominant compared to {@code target}
     * @return the merged location
     */

        // don't merge
    }

    @Override
    protected void mergeBuildBase_Resources(
            BuildBase.Builder builder,
            BuildBase target,
            BuildBase source,
            boolean sourceDominant,
            Map<Object, Object> context) {
        // don't merge
    }

    @Override
    protected void mergeBuildBase_TestResources(

    @Test
    void mergeEmptyMetadata() throws Exception {
        Metadata metadata = new Metadata();
        assertFalse(metadata.merge(new Metadata()));
    }

    @Test
    void mergeDifferentGAV() throws Exception {
        // merge implicitly assumes that merge is only called on the same GAV and does not perform any validation here!
        Metadata source = new Metadata();
        source.setArtifactId("source-artifact");

    }

    @Deprecated
    public void merge(File existing, File result) throws RepositoryException {
        merge(existing != null ? existing.toPath() : null, result != null ? result.toPath() : null);
    }

    @Override
    public void merge(Path existing, Path result) throws RepositoryException {
        Metadata recessive = read(existing);

        merge(recessive);

        write(result, metadata);

        return path;
    }

    public void merge(File existing, File result) throws RepositoryException {
        merge(existing != null ? existing.toPath() : null, result != null ? result.toPath() : null);
    }

    @Override
    public void merge(Path existing, Path result) throws RepositoryException {
        Metadata recessive = read(existing);

        merge(recessive);

        write(result, metadata);