public function evaluate($code)
 {
     $this->reset();
     try {
         $this->output = $this->sandbox->execute($code);
         $this->executionTime = $this->sandbox->execution_time;
         $success = true;
         if (!is_null($this->sandbox->get_last_error())) {
             $this->addError($this->sandbox->get_last_error());
         }
     } catch (\Exception $e) {
         $this->addError(array('type' => get_class($e), 'message' => $e->getMessage(), 'file' => $e->getFile(), 'line' => $e->getLine()));
         $success = false;
     }
     return $success;
 }