function testAsXml()
 {
     $root = new IsterXmlNode(ISTER_XML_TAG, 1, 'root');
     $node1 = new IsterXmlNode(ISTER_XML_TAG, 2, 'node');
     $node2 = new IsterXmlNode(ISTER_XML_TAG, 2, 'node');
     $root->append($node1);
     $root->append($node2);
     $result = $root->asXML();
     $expected = '<root><node/><node/></root>';
     $this->assertFalse(strcmp($expected, $result));
     //print $result;
 }