code: func VerifyAPIServerBindAddress(address string) error {
  	ip := net.ParseIP(address)
  	if ip == nil {
  		return errors.Errorf("cannot parse IP address: %s", address)
  	}
  	if !ip.IsGlobalUnicast() {
  		return errors.Errorf("cannot use %q as the bind address for the API Server", address)
  	}
  	return nil
  }
docs: // VerifyAPIServerBindAddress can be used to verify if a bind address for the API Server is 0.0.0.0,
  // in which case this address is not valid and should not be used.