code: func NewDNSProviderConfig(config *Config) (*DNSProvider, error) {
  	if config == nil {
  		return nil, errors.New("route53: the configuration of the Route53 DNS provider is nil")
  	}
  
  	retry := customRetryer{}
  	retry.NumMaxRetries = config.MaxRetries
  	sessionCfg := request.WithRetryer(aws.NewConfig(), retry)
  
  	sess, err := session.NewSessionWithOptions(session.Options{Config: *sessionCfg})
  	if err != nil {
  		return nil, err
  	}
  
  	cl := route53.New(sess)
  	return &DNSProvider{client: cl, config: config}, nil
  }
docs: // NewDNSProviderConfig takes a given config ans returns a custom configured DNSProvider instance