code: public static FastDateFormat getDateTimeInstance(
              int dateStyle, int timeStyle, TimeZone timeZone) {
          return getDateTimeInstance(dateStyle, timeStyle, timeZone, null);
      }
docs: <p>Gets a date/time formatter instance using the specified style and
  time zone in the default locale.</p>
  
  @param dateStyle  date style: FULL, LONG, MEDIUM, or SHORT
  @param timeStyle  time style: FULL, LONG, MEDIUM, or SHORT
  @param timeZone  optional time zone, overrides time zone of
  formatted date
  @return a localized standard date/time formatter
  @throws IllegalArgumentException if the Locale has no date/time
  pattern defined
  @since 2.1