code: func IsNTFormat(r io.Reader) (bool, io.Reader) {
  	firstChar := make([]byte, 1)
  	multi := io.MultiReader(bytes.NewReader(firstChar), r)
  	if _, err := r.Read(firstChar); err != nil {
  		return false, multi
  	}
  	return bytes.Equal(firstChar, []byte{'<'}), multi
  }
docs: // Loosely detect if a ntriples format contrary to a binary format
  // Used for retro compatibilty when changing file format on existing stores
  // Detecttion work with ntriples format flushed by this library (i.e. no comment, no spaces, ...)