/**
  * 
  * Returns a DomDocument containing the kaltura failure
  * @param KalturaFailure $kalturaFailure
  * @param unknown_type $rootNodeName
  * @return DomDocument
  */
 public static function toXml(KalturaFailure $kalturaFailure, $rootNodeName = 'data')
 {
     $dom = new DOMDocument("1.0");
     $failureNode = $dom->createElement($rootNodeName);
     $dom->appendChild($failureNode);
     $fieldNode = $dom->createElement("Field", $kalturaFailure->getField());
     $failureNode->appendChild($fieldNode);
     $outputReferenceNode = $dom->createElement("OutputReference");
     $failureNode->appendChild($outputReferenceNode);
     KalturaFailure::setElementValue($dom, $outputReferenceNode, $kalturaFailure->getOutputReferenceValue(), $kalturaFailure->getField());
     $actualOutputNode = $dom->createElement("ActualOutput");
     $failureNode->appendChild($actualOutputNode);
     KalturaFailure::setElementValue($dom, $actualOutputNode, $kalturaFailure->getActualValue(), $kalturaFailure->getField());
     $assertNode = $dom->createElement("Assert");
     $failureNode->appendChild($assertNode);
     KalturaFailure::setElementValue($dom, $assertNode, $kalturaFailure->getAssert());
     if (!is_null($kalturaFailure->getMessage())) {
         $messageNode = $dom->createElement("Message");
         $failureNode->appendChild($messageNode);
         KalturaFailure::setElementValue($dom, $messageNode, $kalturaFailure->getMessage());
     }
     return $dom;
 }