code: private static void checkTokenName(String namedOutput) {
      if (namedOutput == null || namedOutput.length() == 0) {
        throw new IllegalArgumentException(
          "Name cannot be NULL or emtpy");
      }
      for (char ch : namedOutput.toCharArray()) {
        if ((ch >= 'A') && (ch <= 'Z')) {
          continue;
        }
        if ((ch >= 'a') && (ch <= 'z')) {
          continue;
        }
        if ((ch >= '0') && (ch <= '9')) {
          continue;
        }
        throw new IllegalArgumentException(
          "Name cannot be have a '" + ch + "' char");
      }
    }
docs: Checks if a named output name is valid token.
  
  @param namedOutput named output Name
  @throws IllegalArgumentException if the output name is not valid.