@Test
public void testIsEndOfMonth() {

    // want to be in the middle of a year
    int month = 5;
    todayGerman.set(Calendar.MONTH, month);
    CalendarUtils.endOfMonth(todayGerman);
    Date start = todayGerman.getTime();
    assertTrue(CalendarUtils.isEndOfMonth(todayGerman));
    assertEquals(start, todayGerman.getTime());
    todayGerman.add(Calendar.MILLISECOND, -1);
    assertFalse(CalendarUtils.isEndOfMonth(todayGerman));
    // sanity: calendar must not be changed
}