### Question:
DateTimesHelper { public String toString(T dateTime) { return toDateTime(dateTime).toString(ISODateTimeFormat.dateHourMinuteSecond()); } DateTimesHelper(Class<T> dateTimeClass, Class<D> dateClass); T toDateTime(Calendar calendar); T toDateTime(Instant instant, String timeZoneId); T toDateTime(DateTime dateTime); T toDateTime(String dateTime, String timeZoneId); T toDateTimeWithTimeZone(String dateTime); String dateToString(D date); DateTime toDateTime(T dateTime); Calendar toCalendar(T dateTime); Calendar toCalendar(T dateTime, Locale locale); String toString(T dateTime); String toStringWithTimeZone(T dateTime); String toStringForTimeZone(T dateTime, String newZoneID);  }### Answer:
@Test public void testToString_fromApiDateTime() { Assert.assertEquals(stringDateTime1, dateTimesHelper.toString(apiDateTime1)); Assert.assertEquals(stringDateTime2, dateTimesHelper.toString(apiDateTime2)); Assert.assertEquals(stringDateTime3, dateTimesHelper.toString(apiDateTime3)); }