-->

#### What this PR does / why we need it:

#### Which issue(s) this PR is related to:
<!--
Please link relevant issues to help with tracking.

To automatically close the linked issue(s) when this PR is merged,
add the word "Fixes" before the issue number or link.
Do not use "Fixes" if the PR is of kind `failing-test` or `flake`.

Reference KEPs when applicable in addition to specific issues.

Examples:

    // When elements compare as equal (both C's have same letter), our merge should always return C1
    // before C2, since C1 is from the first iterator.

    Iterator<TestDatum> merged =
        Iterators.mergeSorted(ImmutableList.of(left.iterator(), right.iterator()), comparator);

    ImmutableList<TestDatum> result = ImmutableList.copyOf(merged);

    assertThat(result)
        .containsExactly(

    // 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

	combined := Mask(atomic.LoadUint64(&ps.types))
	combined.Merge(Mask(mask.Mask()))
	atomic.StoreUint64(&ps.types, uint64(combined))

	go func() {
		<-doneCh

		ps.Lock()
		defer ps.Unlock()
		var remainTypes Mask
		for i, s := range ps.subs {
			if s == sub {
				ps.subs = append(ps.subs[:i], ps.subs[i+1:]...)
			} else {
				remainTypes.Merge(s.types)
			}
		}

        <artifactId>default</artifactId>
        <version>3.0</version>
        <configuration>
          <defaults><!-- equivalent to combine.children="merge" combine.self="merge" -->
            <!-- merge the content of the configuration element according to element name -->
            <parent>child</parent>
            <child>child</child>
            <parent-only>parent</parent-only>

        String dateBefore = gregorianDate();

        RemoteSnapshotMetadata metadata =
                new RemoteSnapshotMetadata(new DefaultArtifact("a:b:1-SNAPSHOT"), new Date(), null);
        metadata.merge(new Metadata());

        String dateAfter = gregorianDate();

        String ts = metadata.metadata.getVersioning().getSnapshot().getTimestamp();
        String datePart = DATE_FILTER.matcher(ts).replaceAll("");

            parent.appendChild(chapter);
            chapter.setAttribute("id", classDoc.getId());
            descriptionRenderer.renderTo(classDoc, chapter);
            merge(classDoc, chapter);
        } finally {
            listener.finish();
        }
    }

    void merge(ClassDoc classDoc, Element chapter) {
        for (ClassDocMemberRenderer memberRenderer : memberRenderers) {
            memberRenderer.renderSummaryTo(classDoc, chapter);

    if [[ "$(git rev-parse --abbrev-ref HEAD)" == "pull_branch" ]]; then
        # TF's CI runs 'git fetch origin "pull/PR#/merge:pull_branch"'
        # To get the as-merged branch during the CI tests
        git diff --diff-filter ACMRT --name-only pull_branch^ pull_branch > $BATS_FILE_TMPDIR/changed_files
    else
        # If the branch is not present, then diff against origin/master

              <include>org.apache.maven.toolchain.merge</include>
            </includes>
            <excludes>
              <!--              <exclude>org.apache.maven.toolchain.building.DefaultToolchainsBuilder#DefaultToolchainsBuilder():CONSTRUCTOR_REMOVED</exclude>-->

If a conditional GET was successful, responses from the network and cache are merged as directed by the spec.

## Follow-up Requests