@Test
public void testSerializeDate() {

  Calendar d = Calendar.getInstance();
  d.set(Calendar.DAY_OF_MONTH, 2);
  d.set(Calendar.HOUR, 5);
  d.set(Calendar.HOUR_OF_DAY, 5);
  d.set(Calendar.MINUTE, 59);
  d.set(Calendar.SECOND, 13);
  d.set(Calendar.MILLISECOND, 0);
  Date date = d.getTime();
  String serializedDate = df.format(date) + "T05:59:13Z";
  assertEquals(serializedDate, IndexUtils.serializeDate(date));
}