code: def ack(self, delivery_tag, multiple=False):
          '''
          Acknowledge delivery of a message.  If multiple=True, acknowledge up-to
          and including delivery_tag.
          '''
          args = Writer()
          args.write_longlong(delivery_tag).\
              write_bit(multiple)
  
          self.send_frame(MethodFrame(self.channel_id, 60, 80, args)f ack(self, delivery_tag, multiple=False):
          '''
          Acknowledge delivery of a message.  If multiple=True, acknowledge up-to
          and including delivery_tag.
          '''
          args = Writer()
          args.write_longlong(delivery_tag).\
              write_bit(multiple)
  
          self.send_frame(MethodFrame(self.channel_id, 60, 80, args))
docs: Acknowledge delivery of a message.  If multiple=True, acknowledge up-to
          and including delivery_tag.