code: func FileContainsAnyBytes(fs Fs, filename string, subslices [][]byte) (bool, error) {
  	f, err := fs.Open(filename)
  	if err != nil {
  		return false, err
  	}
  	defer f.Close()
  
  	return readerContainsAny(f, subslices...), nil
  }
docs: // Check if a file contains any of the specified byte slices.