code: func (i *Identity) HasDNSNames(dnsNames []string) bool {
  	if i.XCert == nil {
  		return false
  	}
  	set := utils.StringsSet(i.XCert.DNSNames)
  	for _, dnsName := range dnsNames {
  		if _, ok := set[dnsName]; !ok {
  			return false
  		}
  	}
  	return true
  }
docs: // HasDNSNames returns true if TLS certificate has required DNS names