code: func (enc *Encoding) EncodedLen(n int) int {
  
  	// Fast path!
  	if n == enc.base256BlockLen {
  		return enc.baseXBlockLen
  	}
  
  	nblocks := n / enc.base256BlockLen
  	out := nblocks * enc.baseXBlockLen
  	rem := n % enc.base256BlockLen
  	if rem > 0 {
  		out += int(math.Ceil(float64(rem*8) / enc.logOfBase))
  	}
  	return out
  }
docs: // EncodedLen returns the length in bytes of the baseX encoding
  // of an input buffer of length n