@Test
 public void testJodaDateTimeConverter() {
   DateTime dateTime = new DateTime(2012, 8, 21, 6, 35, 0, DateTimeZone.UTC);
   Assert.assertEquals(
       "2012\\-08\\-21T06\\:35\\:00.000Z",
       DateTimeConverters.JodaDateTimeConverter.INSTANCE.convert(dateTime));
 }
 @Test
 public void testJodaDateTimeConverterWithNullValue() {
   Assert.assertNull(DateTimeConverters.JodaDateTimeConverter.INSTANCE.convert(null));
 }