code: func (b base57) Encode(u uuid.UUID) string {
  	var num big.Int
  	num.SetString(strings.Replace(u.String(), "-", "", 4), 16)
  
  	// Calculate encoded length.
  	factor := math.Log(float64(25)) / math.Log(float64(b.alphabet.Length()))
  	length := math.Ceil(factor * float64(len(u)))
  
  	return b.numToString(&num, int(length))
  }
docs: // Encode encodes uuid.UUID into a string using the least significant bits
  // (LSB) first according to the alphabet. if the most significant bits (MSB)
  // are 0, the string might be shorter.