code: func (t Target) String() string {
  	var via string
  	if t.Mode == seesaw.HCModeDSR {
  		via = fmt.Sprintf(" (via %s mark %d)", t.Host, t.Mark)
  	}
  	return fmt.Sprintf("%s %s%s", t.addr(), t.Mode, via)
  }
docs: // String returns the string representation of a healthcheck target.