* @param serializer a serializer object.
     * @param tagName a tagName object.
     * @throws IOException IOException if any.
     */
    private void writeCoreExtension(CoreExtension coreExtension, String tagName, XmlSerializer serializer)
            throws IOException {
        serializer.startTag(NAMESPACE, tagName);
        if (coreExtension.getGroupId() != null) {
            serializer

     * @param tagName a tagName object.
     * @throws XmlPullParserException XmlPullParserException if
     * any.
     * @return boolean
     */
    private boolean checkFieldWithDuplicate(
            XmlPullParser parser, String tagName, String alias, java.util.Set<String> parsed)
            throws XmlPullParserException {
        if (!(parser.getName().equals(tagName) || parser.getName().equals(alias))) {

            target.append("<${element.tagName}")
            for (int i = 0; i < element.attributes.length; i++) {
                Attr attr = element.attributes.item(i)
                target.append(" $attr.name=\"$attr.value\"")
            }

            element.childNodes.findAll { it instanceof Text }.each {
                assert it.textContent != null : "Found null text element in <$element.tagName>"
            }

  <defaults>
    <default>
      <key>package</key>
      <value>org.apache.maven.cli.internal.extension.model</value>
    </default>
  </defaults>

  <classes>
    <class rootElement="true" xml.tagName="extensions" xsd.compositor="sequence">
      <name>CoreExtensions</name>
      <description>Extensions to load.</description>
      <version>1.0.0+</version>
      <fields>
        <field>

		if se, ok := t.(xml.StartElement); ok {
			tagName := se.Name.Local
			switch tagName {
			case "AllowQuotedRecordDelimiter":
				var b bool
				if err = d.DecodeElement(&b, &se); err != nil {
					return err
				}
				args.AllowQuotedRecordDelimiter = b
			default:
				var s string
				if err = d.DecodeElement(&s, &se); err != nil {
					return err
				}
				switch tagName {
				case "FileHeaderInfo":

        // start of tag marker
        scanner.next(2);

        // tag name
        scanner.mark();
        scanner.find(END_TAG_NAME);
        String tagName = scanner.region();
        visitor.onStartJavadocTag(tagName);
        scanner.skip(WHITESPACE_WITH_EOL);

        // value
        if (!scanner.lookingAt('}')) {
            scanner.mark();
            scanner.find('}');

      <value>org.apache.maven.artifact.repository.metadata</value>
    </default>
  </defaults>
  <classes>
    <class rootElement="true" xml.tagName="metadata" java.clone="deep">
      <name>Metadata</name>
      <version>1.0.0+</version>
      <fields>
        <field xml.attribute="true" xml.tagName="modelVersion">
          <name>modelVersion</name>
          <version>1.1.0+</version>
          <type>String</type>

          <type>String</type>
          <description></description>
        </field>
        <field xml.tagName="role-hint">
          <name>roleHint</name>
          <type>String</type>
          <description></description>
        </field>
        <field xml.tagName="field-name">
          <name>fieldName</name>
          <required>true</required>
          <type>String</type>

  </description>
  <defaults>
    <default>
      <key>package</key>
      <value>org.apache.maven.plugin.resources.remote</value>
    </default>
  </defaults>
  <classes>
    <class rootElement="true" xml.tagName="remoteResourcesBundle">
      <name>RemoteResourcesBundle</name>
      <version>1.1.0</version>
      <description>Root element of the remote-resources.xml file.</description>
      <fields>
        <field>

  <defaults>
    <default>
      <key>package</key>
      <value>org.apache.maven.plugin.resources.remote</value>
    </default>
  </defaults>
  <classes>
    <class rootElement="true" xml.tagName="supplementalDataModels" xsd.compositor="sequence">
      <name>SupplementalDataModel</name>
      <version>1.0.0</version>
      <description>Root element of the supplemental-models.xml file.</description>
      <fields>