func (e *dataUsageEntry) addChild(hash dataUsageHash) {
	if _, ok := e.Children[hash.Key()]; ok {
		return
	}
	if e.Children == nil {
		e.Children = make(dataUsageHashMap, 1)
	}
	e.Children[hash.Key()] = struct{}{}
}

// Create a clone of the entry.
func (e dataUsageEntry) clone() dataUsageEntry {
	// We operate on a copy from the receiver.
	if e.Children != nil {
		ch := make(dataUsageHashMap, len(e.Children))

		var compact bool
		if flat.Objects < dataScannerCompactLeastObject {
			compact = true
		} else {
			// Compact if we only have objects as children...
			compact = true
			for k := range into.Children {
				if v, ok := f.newCache.Cache[k]; ok {
					if len(v.Children) > 0 || v.Objects > 1 {
						compact = false
						break
					}
				}
			}

		}
		if compact {

                XmlNode dom = server.getDelegate().getConfiguration();
                List<XmlNode> children = dom.getChildren().stream()
                        .filter(c -> !"wagonProvider".equals(c.getName()))
                        .collect(Collectors.toList());
                dom = new XmlNodeImpl(dom.getName(), null, null, children, null);
                PlexusConfiguration config = XmlPlexusConfiguration.toPlexusConfiguration(dom);

                   JDK6-like APIs.

                   So instead, we use javac9, which doesn't lead to this error.
              -->
              <compilerArgs combine.children="append">
                <arg>-J-Xbootclasspath/p:${settings.localRepository}/com/google/errorprone/javac/${javac.version}/javac-${javac.version}.jar</arg>
              </compilerArgs>
            </configuration>

    <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>

    <pluginManagement>
      <plugins>
        <plugin>
          <groupId>org.apache.rat</groupId>
          <artifactId>apache-rat-plugin</artifactId>
          <configuration>
            <excludes combine.children="append">
              <exclude>lifecycle-executor.txt</exclude>
              <exclude>plugin-manager.txt</exclude>
              <exclude>project-builder.txt</exclude>

  ops->filesystem_ops->copy_file = tf_posix_filesystem::CopyFile;
  ops->filesystem_ops->path_exists = tf_posix_filesystem::PathExists;
  ops->filesystem_ops->stat = tf_posix_filesystem::Stat;
  ops->filesystem_ops->get_children = tf_posix_filesystem::GetChildren;
}

void TF_InitPlugin(TF_FilesystemPluginInfo* info) {
  info->plugin_memory_allocate = plugin_memory_allocate;
  info->plugin_memory_free = plugin_memory_free;