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 {{{../../api/maven-api-model/maven.html}Descriptor Reference}}

  @J2ktIncompatible
  @GwtIncompatible // used only in GwtIncompatible tests
  private interface Merger {

    ListenableFuture<List<String>> merged(ListenableFuture<String> a, ListenableFuture<String> b);

    Merger allMerger =
        new Merger() {
          @Override
          public ListenableFuture<List<String>> merged(
              ListenableFuture<String> a, ListenableFuture<String> b) {

  @J2ktIncompatible
  @GwtIncompatible // used only in GwtIncompatible tests
  private interface Merger {

    ListenableFuture<List<String>> merged(ListenableFuture<String> a, ListenableFuture<String> b);

    Merger allMerger =
        new Merger() {
          @Override
          public ListenableFuture<List<String>> merged(
              ListenableFuture<String> a, ListenableFuture<String> b) {

            Properties merged = new Properties();
            if (sourceDominant) {
                merged.putAll(target.getProperties());
                putAll(merged, source.getProperties(), CHILD_DIRECTORY_PROPERTY);
            } else {
                putAll(merged, source.getProperties(), CHILD_DIRECTORY_PROPERTY);
                merged.putAll(target.getProperties());
            }

                merged.put(key, element);
            }

            for (Repository element : recessive) {
                Object key = getRepositoryKey(element);
                if (!merged.containsKey(key)) {
                    merged.put(key, element);
                }
            }

            target.setRepositories(new ArrayList<>(merged.values()));
        }
    }

    /**
     * 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(

        Properties merged = new Properties();
        if (sourceDominant) {
            merged.putAll(target.getProperties());
            merged.putAll(source.getProperties());
        } else {
            merged.putAll(source.getProperties());
            merged.putAll(target.getProperties());
        }
        target.setProperties(merged);
        target.setLocation(

            <goals>
              <goal>velocity</goal>
            </goals>
            <phase>generate-sources</phase>
            <configuration>
              <templates>
                <template>merger.vm</template>
                <template>transformer.vm</template>
                <template>reader-stax.vm</template>
                <template>writer-stax.vm</template>
              </templates>

              <models>
                <model>target/mdo/maven.mdo</model>
              </models>
              <templates>
                <template>src/main/mdo/model-v3.vm</template>
                <template>src/main/mdo/merger.vm</template>
                <template>src/main/mdo/transformer.vm</template>
                <template>src/main/mdo/reader.vm</template>
                <template>src/main/mdo/reader-ex.vm</template>

        final Set<String> merged = new LinkedHashSet<>();

        if (array1 != null) {
            Collections.addAll(merged, array1);
        }

        if (array2 != null) {
            Collections.addAll(merged, array2);
        }

        return merged.toArray(new String[merged.size()]);
    }

    /**
     * Merges two Kind arrays, maintaining uniqueness.
     */