Update comment :param:`id` with values from :param:`data` and return
        updated comment.

def update(self, id, data):
        """
        Update comment :param:`id` with values from :param:`data` and return
        updated comment.
        """
        self.db.execute([
            'UPDATE comments SET',
            ','.join(key + '=' + '?' for key in data),
            'WHERE id=?;'],
            list(data.values()) + [id])

        return self.get(id)