def comment_vote(self, comment_id, score):
        """Lets you vote for a comment (Requires login).

        Parameters:
            comment_id (int):
            score (str): Can be: up, down.
        """
        params = {'score': score}
        return self._get('comments/{0}/votes.json'.format(comment_id), params,
                         method='POST', auth=True)