/**
  * Transforms FormElement_List into a SimpleXMLElement
  *
  * @param SimpleXMLElement $root        The node to which the FormElement is attached (passed by reference)
  * @param array            &$xmlMapping The correpondance between real ids and xml IDs
  */
 public function exportToXml(SimpleXMLElement $root, &$xmlMapping)
 {
     parent::exportToXML($root, $xmlMapping);
     if ($this->getBind() && $this->shouldBeBindXML()) {
         $child = $root->addChild('bind');
         $bf = new Tracker_FormElement_Field_List_BindFactory();
         $child->addAttribute('type', $bf->getType($this->getBind()));
         $this->getBind()->exportToXML($child, $xmlMapping);
     }
 }