public function grade()
    {
        $url = Config::get('url.grade_class_exam');

        $response = $this->request('get', [$url]);

        $body = $this->checkAndThrow($response);

        return Parser::table($body, '#DataGrid1', [
            'year', 'term', 'name', 'number', 'date', 'grade_all', 'grade_listening',
            'grade_reading', 'grade_writing', 'grade_synthesizing',
        ], 10);
    }