'Given a course_id, filename, and rows (each row is an iterable of
strings), write the rows to the storage backend in csv format.'

def store_rows(self, course_id, filename, rows):

    output_buffer = ContentFile('')
    csvwriter = csv.writer(output_buffer)
    csvwriter.writerows(self._get_utf8_encoded_rows(rows))
    output_buffer.seek(0)
    self.store(course_id, filename, output_buffer)
