code: func ASCIIToTrytes(s string) (Trytes, error) {
  	if !asciiRegex.MatchString(s) {
  		return "", ErrInvalidASCIIInput
  	}
  
  	trytesStr := ""
  
  	for _, c := range s {
  		trytesStr += string(TryteAlphabet[c%27])
  		trytesStr += string(TryteAlphabet[(c-c%27)/27])
  	}
  
  	return NewTrytes(trytesStr)
  }
docs: // ASCIIToTrytes converts an ascii encoded string to trytes.