### Question:
Randoms { public static DateTime randomDateTime() { final long timeMillis = (randomLong() & 0x0000_7fff_ffff_ffffL) + DAY_MILLIS; final int offsetTotalMinutes = 15 * (randomInt(96) - 48); final DateTimeZone dateTimeZone = DateTimeZone.forOffsetMillis(1000 * 60 * offsetTotalMinutes); return new DateTime(timeMillis, dateTimeZone); }  static String randomString(final int length); static char randomChar(); static String randomString(); static String randomEmailAddress(); static String randomPhoneNumber(); static DateTime randomDateTime(); static LocalDateTime randomLocalDateTime(); static LocalDate randomLocalDate(); static LocalTime randomLocalTime(); static E randomEnum(final Class<E> enumClass); static Set<E> randomEnumSet(final Class<E> enumClass); static E randomEnumInSet(final Set<E> enumSet); static Set<T> randomSubset(final Set<T> set); static int randomInt(final int max); static float randomFloat(); static double randomDouble(); static long randomLong(); static boolean randomBoolean(); static BigDecimal randomBigDecimal(final int maxValue, final int precision); static BigDecimal randomPositiveBigDecimal(final int maxValue, final int precision); static int randomIntInRange(final int from, final int to); static String randomCreditCardNumber(final String prefix); static String randomId(); static T randomItem(final T[] array); static T randomItem(final Collection<T> collection); static Set<String> randomIdSet();  }### Answer:
@Test public void shouldReturnRandomDateTime() { final Set<DateTime> randomDateTimes = new HashSet<>(); for (int n = 0; n < SAMPLE_SIZE; n++) { final DateTime randomDateTime = Randoms.randomDateTime(); assertNotNull(randomDateTime); randomDateTimes.add(randomDateTime); } assertEquals("Random sample DateTimes should be unique", SAMPLE_SIZE, randomDateTimes.size()); }