public static CronPattern of(String pattern) {
		return new CronPattern(pattern);
	}
@Test
	public void lastTest() {
		// 每月最后一天的任意时间
		CronPattern pattern = CronPattern.of("* * * L * ?");
		assertMatch(pattern, "2017-07-31 04:20:00");
		assertMatch(pattern, "2017-02-28 04:20:00");

		// 最后一个月的任意时间
		pattern = CronPattern.of("* * * * L ?");
		assertMatch(pattern, "2017-12-02 04:20:00");

		// 任意天的最后时间
		pattern = CronPattern.of("L L L * * ?");
		assertMatch(pattern, "2017-12-02 23:59:59");
	}