code: func (c checkKey) String() string {
  	return fmt.Sprintf("%v:%d/%v backend %v:%d/%v %v %v port %d (%s)",
  		c.vserverIP, c.servicePort, c.serviceProtocol,
  		c.backendIP, c.servicePort, c.serviceProtocol,
  		c.healthcheckMode, c.healthcheckType, c.healthcheckPort, c.name)
  }
docs: // String returns the string representation of a checkKey.