public static CronPattern of(String pattern) {
		return new CronPattern(pattern);
	}
@Test
	public void patternNegativeTest() {
		// -4表示倒数的数字，此处在小时上，-4表示 23 - 4，为19
		CronPattern pattern = CronPattern.of("* 0 -4 * * ?");
		assertMatch(pattern, "2017-02-09 19:00:00");
		assertMatch(pattern, "2017-02-19 19:00:33");
	}