docs: private static int determineConsecutiveTextCount(CharSequence msg, int startpos) {
      int len = msg.length();
      int idx = startpos;
      while (idx < len) {
        char ch = msg.charAt(idx);
        int numericCount = 0;
        while (numericCount < 13 && isDigit(ch) && idx < len) {
          numericCount++;
          idx++;
          if (idx < len) {
            ch = msg.charAt(idx);
          }
        }
        if (numericCount >= 13) {
          return idx - startpos - numericCount;
        }
        if (numericCount > 0) {
          //Heuristic: All text-encodable chars or digits are binary encodable
          continue;
        }
        ch = msg.charAt(idx);
  
        //Check if character is encodable
        if (!isText(ch)) {
          break;
        }
        idx++;
      }
      return idx - startpos;
    }