code: public DateFormat getDateTimeFormat(int dateStyle, int timeStyle, Locale loc) {
          return formatHelper(this, ULocale.forLocale(loc), dateStyle, timeStyle);
      }
docs: <strong>[icu]</strong> Returns a <code>DateFormat</code> appropriate to this calendar.
  Subclasses wishing to specialize this behavior should override
  {@link #handleGetDateFormat}.