public function getOrderArticles($blExcludeCanceled = false)
    {
        // checking set value
        if ($blExcludeCanceled) {
            return $this->_getArticles(true);
        } elseif ($this->_oArticles === null) {
            $this->_oArticles = $this->_getArticles();
        }

        return $this->_oArticles;
    }