code: func (d *Driver) PendingMessage() string {
  	if len(d.Messages) < 1 {
  		return ""
  	}
  	m := d.Messages[0]
  	d.Messages = d.Messages[1:]
  
  	return m
  }
docs: // PendingMessages returns messages to be sent as notifications to pebble
  // (Not intended to be used directly)