code: def save_to_s3(self, bucket):
          
          n = 0
          m = self.read()
          while m:
              n += 1
              key = bucket.new_key('%s/%s' % (self.id, m.id))
              key.set_contents_from_string(m.get_body())
              self.delete_message(m)
              m = self.read()
          return n
docs: Read all messages from the queue and persist them to S3.
          Messages are stored in the S3 bucket using a naming scheme of::
          
              <queue_id>/<message_id>
          
          Messages are deleted from the queue after being saved to S3.
          Returns the number of messages saved.