function getDoc()
 {
     $doc = new IsterXmlNode(ISTER_XML_DOCUMENT, 0);
     $root = new IsterXmlNode(ISTER_XML_TAG, 1, 'root');
     $node1 = new IsterXmlNode(ISTER_XML_TAG, 2, 'node');
     $node2 = new IsterXmlNode(ISTER_XML_TAG, 2, 'node');
     $doc->append($root);
     $doc->append($node1);
     $doc->append($node2);
     return $doc;
 }