code: func (hc *TCPChecker) String() string {
  	attr := []string{}
  	if hc.Secure {
  		attr = append(attr, "secure")
  		if hc.TLSVerify {
  			attr = append(attr, "verify")
  		}
  	}
  	var s string
  	if len(attr) > 0 {
  		s = fmt.Sprintf(" [%s]", strings.Join(attr, "; "))
  	}
  	return fmt.Sprintf("TCP%s %s", s, hc.Target)
  }
docs: // String returns the string representation of a TCP healthcheck.