code: public static List<SecretShare> split(String secretString, int total, int threshold) {
          BigInteger secret = SasUtils.encodeStringToInteger(secretString);
          return split(secret, total, threshold);
      }
docs: Split the secret into the specified total number of shares. Specified minimum threshold of shares will need to be
  present in order to join them back into the secret. Polynomial coefficients and prime modulo will be randomly
  chosen.
  
  @param secretString string to convert into number and split into shares
  @param total number of shares to generate
  @param threshold minimum number of shares required to successfully join back the secret
  @return list of shares