code: func buildDNSCapabilities(dnsConfig *runtimeapi.DNSConfig) *cniDNSConfig {
  	if dnsConfig != nil {
  		return &cniDNSConfig{
  			Servers:  dnsConfig.Servers,
  			Searches: dnsConfig.Searches,
  			Options:  dnsConfig.Options,
  		}
  	}
  
  	return nil
  }
docs: // buildDNSCapabilities builds cniDNSConfig from runtimeapi.DNSConfig.