public function __construct($target_root)
 {
     parent::__construct($target_root);
 }
 protected function translate_question_text($text, $text_format = self::FORMAT_HTML, $question = null)
 {
     $result = parent::translate_question_text($text, $text_format, $question);
     $pattern = "/^\\{[a-zA-Z_][a-zA-Z0-9_]*\\}/";
     $datasets = isset($question->options->datasets) ? $question->options->datasets : array();
     foreach ($datasets as $dataset) {
         $name = '{' . $dataset->name . '}';
         $replace = '<printedVariable identifier="' . $dataset->name . '" />';
         $result = str_replace($name, $replace, $result);
     }
     return $result;
 }