/**
  * @param boolean $batch true to build xml suitable to append to a batch xml 
  * request, false to build an xml to post this single item. Defaults to 
  * false.
  * @return string The rendered xml for this item.
  */
 function getXml($batch = false)
 {
     $xml = $batch ? new XmlBuilder('') : new XmlBuilder();
     $entry_attrs = $batch ? array() : array('xmlns' => 'http://www.w3.org/2005/Atom', 'xmlns:g' => 'http://base.google.com/ns/1.0');
     $xml->Push('entry', $entry_attrs);
     if ($this->_id) {
         $xml->Element('id', $this->_id);
     }
     if ($this->_author) {
         $this->_author->addToXml($xml);
     }
     $this->_title->addToXml($xml);
     $this->_description->addToXml($xml);
     foreach ($this->_links as $link) {
         $link->addToXml($xml);
     }
     foreach ($this->_attributes as $attr) {
         $attr->addToXml($xml);
     }
     if ($this->_draft) {
         // <app:control> <app:draft>yes</app:draft> </app:control>
         $xml->Push('app:control', array('xmlns:app' => 'http://purl.org/atom/app#'));
         $xml->Element('app:draft', 'yes');
         $xml->Pop('app:control');
     }
     $xml->Pop('entry');
     return $xml->GetXML();
 }