'Return a tuple of the form `(points, max_points)` representing
the aggregate score for the specified chapter and section.'

def _aggregate_section_score(self, chapter_index, section_index):

    score_css = '.chapters>section:nth-of-type({0})    .sections>div:nth-of-type({1})    .hd>span'.format(chapter_index, section_index)
    text_scores = self.q(css=score_css).text
    assert (len(text_scores) == 1)
    text_score = text_scores[0]
    text_score = text_score.split()[0]
    assert ((text_score[0], text_score[(-1)]) == ('(', ')'))
    text_score = text_score.strip('()')
    assert ('/' in text_score)
    score = tuple((int(x) for x in text_score.split('/')))
    assert (len(score) == 2)
    return score
