public void now_Clock() {

    Instant instant = LocalDateTime.of(2010, 12, 31, 0, 0).toInstant(ZoneOffset.UTC);
    Clock clock = Clock.fixed(instant, ZoneOffset.UTC);
    YearMonth test = YearMonth.now(clock);
    assertEquals(test.getYear(), 2010);
    assertEquals(test.getMonth(), Month.DECEMBER);
  }

  @Test(expectedExceptions = NullPointerException.class, groups = { "tck" }