code: func newNetrcCredentialHelper(osEnv config.Environment) *netrcCredentialHelper {
  	netrcFinder, netrcfile, err := ParseNetrc(osEnv)
  	if err != nil {
  		tracerx.Printf("bad netrc file %s: %s", netrcfile, err)
  		return nil
  	}
  
  	if netrcFinder == nil {
  		netrcFinder = defaultNetrcFinder
  	}
  
  	return &netrcCredentialHelper{netrcFinder: netrcFinder, skip: make(map[string]bool)}
  }
docs: // NewNetrcCredentialHelper creates a new netrc credential helper using a
  // .netrc file gleaned from the OS environment