docs: public static String ssn(boolean formatted) {
          if (!formatted) {
              return JDefaultNumber.randomNumberString(9);
          } else {
              StringBuffer ssnString = new StringBuffer(JDefaultNumber.randomNumberString(3));
              ssnString.append("-");
              ssnString.append(JDefaultNumber.randomNumberString(2));
              ssnString.append("-");
              ssnString.append(JDefaultNumber.randomNumberString(4));
              return ssnString.toString();
          }
  
      }