code: public static DateFormat getUSDateTimeFormat(int dateStyle, int timeStyle) {
      String pattern = getDatePartOfDateTimePattern(dateStyle) + " " + getTimePartOfDateTimePattern(timeStyle);
      return new SimpleDateFormat(pattern, Locale.US);
    }
docs: Returns the same DateFormat as {@code DateFormat.getDateTimeInstance(dateStyle, timeStyle, Locale.US)}
  in Java 8 or below.