code: func (b *BasePathRealFilenameFs) Stat(name string) (os.FileInfo, error) {
  	fi, err := b.BasePathFs.Stat(name)
  	if err != nil {
  		return nil, err
  	}
  
  	if _, ok := fi.(RealFilenameInfo); ok {
  		return fi, nil
  	}
  
  	filename, err := b.RealPath(name)
  	if err != nil {
  		return nil, &os.PathError{Op: "stat", Path: name, Err: err}
  	}
  
  	return &realFilenameInfo{FileInfo: fi, realFilename: filename}, nil
  }
docs: // Stat returns the os.FileInfo structure describing a given file.  If there is
  // an error, it will be of type *os.PathError.