public long between(DateUnit unit) {
		long diff = end.getTime() - begin.getTime();
		return diff / unit.getMillis();
	}
@Test
	public void betweenWeeksTest(){
		final long betweenWeek = DateUtil.betweenWeek(
				DateUtil.parse("2020-11-21"),
				DateUtil.parse("2020-11-23"), false);

		final long betweenWeek2 = LocalDateTimeUtil.between(
				LocalDateTimeUtil.parse("2020-11-21", "yyy-MM-dd"),
				LocalDateTimeUtil.parse("2020-11-23", "yyy-MM-dd"),
				ChronoUnit.WEEKS);
		assertEquals(betweenWeek, betweenWeek2);
	}