public function GetMetadata($courseId, $versionId, $scope, $format)
 {
     $enum = new Enum();
     $request = new ServiceRequest($this->_configuration);
     $params = array('courseid' => $courseId);
     if (isset($versionId) && $versionId != 0) {
         $params['versionid'] = $versionId;
     }
     $params['scope'] = $enum->getMetadataScope($scope);
     $params['mdformat'] = $enum->getDataFormat($format);
     $request->setMethodParams($params);
     $response = $request->CallService("rustici.course.getMetadata");
     // Return the subset of the xml starting with the top <object>
     return $response;
 }