protected final DateFormat _dateFormat() {
   if (_dateFormat != null) {
     return _dateFormat;
   }
   /* At this point, all timezone configuration should have occured, with respect
    * to default dateformat configuration. But we still better clone
    * an instance as formatters are stateful, not thread-safe.
    */
   DateFormat df = _config.getDateFormat();
   _dateFormat = df = (DateFormat) df.clone();
   // [databind#939]: 26-Sep-2015, tatu: With 2.6, formatter has been (pre)configured
   // with TimeZone, so we should NOT try overriding it unlike with earlier versions
   /*
   TimeZone tz = getTimeZone();
   if (tz != df.getTimeZone()) {
       df.setTimeZone(tz);
   }
   */
   return df;
 }