code: public static boolean isUnixTimeStamp(String timeStamp) {
      if (timeStamp.length() != ComplianceConfigurationKeys.TIME_STAMP_LENGTH) {
        return false;
      }
      try {
        Long.parseLong(timeStamp);
        return true;
      } catch (NumberFormatException e) {
        return false;
      }
    }
docs: Check if a given string is a valid unixTimeStamp