code: func (b *Builder) FilenameParam(enforceNamespace bool, paths ...string) *Builder {
  	for _, s := range paths {
  		switch {
  		case s == "-":
  			b.Stdin()
  		case strings.Index(s, "http://") == 0 || strings.Index(s, "https://") == 0:
  			url, err := url.Parse(s)
  			if err != nil {
  				b.errs = append(b.errs, fmt.Errorf("the URL passed to filename %q is not valid: %v", s, err))
  				continue
  			}
  			b.URL(url)
  		default:
  			b.Path(s)
  		}
  	}
  
  	if enforceNamespace {
  		b.RequireNamespace()
  	}
  
  	return b
  }
docs: // FilenameParam groups input in two categories: URLs and files (files, directories, STDIN)
  // If enforceNamespace is false, namespaces in the specs will be allowed to
  // override the default namespace. If it is true, namespaces that don't match
  // will cause an error.
  // If ContinueOnError() is set prior to this method, objects on the path that are not
  // recognized will be ignored (but logged at V(2)).