public function findModel($id)
    {
        if($this->_model === null) 
        {
            if($this->_model = $id ? Author::findOne($id) : null) 
            {
                return $this->_model;
            } else {
                throw new NotFoundHttpException(Module::t('core', 'The requested model does not exist.'));
            }
        }
    }