try { DateUtils.isSameDay((Calendar) null, (Calendar) null); fail(); } catch (IllegalArgumentException ex) {}
    public void testIsSameDay_Cal() {        GregorianCalendar cal1 = new GregorianCalendar(2004, 6, 9, 13, 45);        GregorianCalendar cal2 = new GregorianCalendar(2004, 6, 9, 13, 45);        assertEquals(true, DateUtils.isSameDay(cal1, cal2));        cal2.add(Calendar.DAY_OF_YEAR, 1);        assertEquals(false, DateUtils.isSameDay(cal1, cal2));        cal1.add(Calendar.DAY_OF_YEAR, 1);        assertEquals(true, DateUtils.isSameDay(cal1, cal2));        cal2.add(Calendar.YEAR, 1);        assertEquals(false, DateUtils.isSameDay(cal1, cal2));    }