String SELF_COMBINATION_MODE_ATTRIBUTE = "combine.self";

    String SELF_COMBINATION_OVERRIDE = "override";

    String SELF_COMBINATION_MERGE = "merge";

    String SELF_COMBINATION_REMOVE = "remove";

    /**
     * In case of complex XML structures, combining can be done based on id.
     */
    String ID_COMBINATION_MODE_ATTRIBUTE = "combine.id";

    /**

    RepositorySystemSession getRepositorySession();

    ProjectBuildingRequest setRepositorySession(RepositorySystemSession repositorySession);

    /**
     * Sets the merge mode used to combine repositories declared in the POM with the repositories specified in this
     * request.
     *
     * @param mode The repository merge mode, must not be {@code null}.

        this.scopes = new HashSet<>();

        addScopes(scopes);
    }

    /**
     * Creates a new filter that combines the specified filters.
     *
     * @param filters The filters to combine, may be {@code null}.
     */
    public CumulativeScopeArtifactFilter(CumulativeScopeArtifactFilter... filters) {
        this.scopes = new HashSet<>();

  <version>1.0</version>
  <packaging>pom</packaging>

  <name>Maven Integration Test :: MNG-2591</name>
  <description>
    Test aggregation of list configuration items for build plugins when using
    'combine.children=append' attribute.
  </description>

  <modules>
    <module>subproject</module>
  </modules>

  <build>
    <pluginManagement>
      <plugins>
        <plugin>

          <stringParams combine.children="append">
            <!-- NOTE: These values are deliberately not in alpha order! -->
            <stringParam>CHILD-1</stringParam>
            <stringParam>CHILD-3</stringParam>
            <stringParam>CHILD-2</stringParam>
            <stringParam>CHILD-4</stringParam>
          </stringParams>
          <listParam combine.children="append">

    <pluginManagement>
      <plugins>
        <plugin>
          <groupId>org.apache.rat</groupId>
          <artifactId>apache-rat-plugin</artifactId>
          <configuration>
            <excludes combine.children="append">
              <exclude>src/assembly/maven/bin/m2.conf</exclude>
              <!-- these are partial scripts, resulting in mvn scripts -->
              <exclude>src/assembly/shared/init</exclude>

          <stringParams combine.children="append">
            <!-- NOTE: These values are deliberately not in alpha order! -->
            <stringParam>CHILD-1</stringParam>
            <stringParam>CHILD-3</stringParam>
            <stringParam>CHILD-2</stringParam>
            <stringParam>CHILD-4</stringParam>
          </stringParams>
          <listParam combine.children="append">

private static final Xpp3Dom[] EMPTY_DOM_ARRAY; public static final String CHILDREN_COMBINATION_MODE_ATTRIBUTE = combine.children; public static final String CHILDREN_COMBINATION_MERGE = merge; public static final String CHILDREN_COMBINATION_APPEND = append; public static final String DEFAULT_CHILDREN_COMBINATION_MODE = merge; public static final String SELF_COMBINATION_MODE_ATTRIBUTE = combine.self; public static final String SELF_COMBINATION_OVERRIDE = override; public static final String SELF_COMBINATION_MERGE...

            or {@code combine.self} attributes to the children of the configuration element:</p>
            <ul>
            <li>{@code combine.children}: available values are {@code merge} (default) and {@code append},</li>
            <li>{@code combine.self}: available values are {@code merge} (default) and {@code override}.</li>

private static final Xpp3Dom[] EMPTY_DOM_ARRAY; public static final String CHILDREN_COMBINATION_MODE_ATTRIBUTE = combine.children; public static final String CHILDREN_COMBINATION_MERGE = merge; public static final String CHILDREN_COMBINATION_APPEND = append; public static final String DEFAULT_CHILDREN_COMBINATION_MODE = merge; public static final String SELF_COMBINATION_MODE_ATTRIBUTE = combine.self; public static final String SELF_COMBINATION_OVERRIDE = override; public static final String SELF_COMBINATION_MERGE...