docs: private static String wordShapeDan1(String s) {
      boolean digit = true;
      boolean upper = true;
      boolean lower = true;
      boolean mixed = true;
      for (int i = 0; i < s.length(); i++) {
        char c = s.charAt(i);
        if (!Character.isDigit(c)) {
          digit = false;
        }
        if (!Character.isLowerCase(c)) {
          lower = false;
        }
        if (!Character.isUpperCase(c)) {
          upper = false;
        }
        if ((i == 0 && !Character.isUpperCase(c)) || (i >= 1 && !Character.isLowerCase(c))) {
          mixed = false;
        }
      }
      if (digit) {
        return "ALL-DIGITS";
      }
      if (upper) {
        return "ALL-UPPER";
      }
      if (lower) {
        return "ALL-LOWER";
      }
      if (mixed) {
        return "MIXED-CASE";
      }
      return "OTHER";
    }