code: func (l *arpaMalformedIP) Execute(c *x509.Certificate) *LintResult {
  	for _, name := range c.DNSNames {
  		name = strings.ToLower(name)
  		var err error
  		if strings.HasSuffix(name, rdnsIPv4Suffix) {
  			// If the name has the in-addr.arpa suffix then it should be an IPv4 reverse
  			// DNS name.
  			err = lintReversedIPAddressLabels(name, false)
  		} else if strings.HasSuffix(name, rdnsIPv6Suffix) {
  			// If the name has the ip6.arpa suffix then it should be an IPv6 reverse
  			// DNS name.
  			err = lintReversedIPAddressLabels(name, true)
  		}
  		// Return the first error as a negative lint result
  		if err != nil {
  			return &LintResult{
  				Status:  Warn,
  				Details: err.Error(),
  			}
  		}
  	}
  
  	return &LintResult{
  		Status: Pass,
  	}
  }
docs: // Execute will check the given certificate to ensure that all of the DNS
  // subject alternate names that specify a reverse DNS name under the respective
  // IPv4 or IPv6 arpa zones are well formed. A Warn LintResult is returned if
  // the name is in a reverse DNS zone but has the wrong number of labels.