code: func (c *confirms) One(confirmed Confirmation) {
  	c.m.Lock()
  	defer c.m.Unlock()
  
  	if c.expecting == confirmed.DeliveryTag {
  		c.confirm(confirmed)
  	} else {
  		c.sequencer[confirmed.DeliveryTag] = confirmed
  	}
  	c.resequence()
  }
docs: // one confirms one publishing and all following in the publishing sequence