/**
     * Convenience method to merge two XML nodes using default settings.
     */
    @Nullable
    public static XmlNode merge(XmlNode dominant, XmlNode recessive) {
        return merge(dominant, recessive, null);
    }

    /**
     * Merges two XML nodes.
     */
    @Nullable
    public static XmlNode merge(

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

                    );

            UpgradeResult merged = result1.merge(result2);

            assertTrue(merged.success(), "Merged result should be successful");
            assertEquals(2, merged.processedPoms().size(), "Should merge processed POMs");
            assertEquals(2, merged.modifiedPoms().size(), "Should merge modified POMs");
            assertTrue(merged.processedPoms().contains(pom1), "Should contain overlapping POM");

type LastMinuteHistogram [sizeLastElemMarker]lastMinuteLatency

// Merge safely merges two LastMinuteHistogram structures into one
func (l LastMinuteHistogram) Merge(o LastMinuteHistogram) (merged LastMinuteHistogram) {
	for i := range l {
		merged[i] = l[i].merge(o[i])
	}
	return merged
}

// Add latency t from object with the specified size.

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

        Model merged = mavenMerger.merge(target, source, true, null);
        assertEquals(
                "SOURCE",
                merged.getArtifactId(),
                "Expected merged artifactId to be SOURCE but was " + merged.getArtifactId());

        merged = mavenMerger.merge(target, source, false, null);
        assertEquals(
                "TARGET",

  public void testAbsent() {
    assertEquals(
        "Map.merge(absent, value, function) should return value",
        v3(),
        getMap()
            .merge(
                k3(),
                v3(),
                (oldV, newV) -> {
                  throw new AssertionFailedError(
                      "Should not call merge function if key was absent");
                }));
    expectAdded(e3());
  }

 * but sometimes changes on release notes.md was brought to master and merged unnoticed,
 * e.g https://github.com/gradle/gradle/pull/25825
 *
 * This script is to check if there is any merge commit that brings changes from release branch to master.
 * Usage: groovy CheckBadMerge.groovy <commit1> <commit2> ...
 * If any "bad" merge commit is found, it will print the details and exit with non-zero code.
 */
class CheckBadMerge {

  public void testAbsent() {
    assertEquals(
        "Map.merge(absent, value, function) should return value",
        v3(),
        getMap()
            .merge(
                k3(),
                v3(),
                (oldV, newV) -> {
                  throw new AssertionFailedError(
                      "Should not call merge function if key was absent");
                }));
    expectAdded(e3());
  }

    }

    @Override
    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);

        // 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(