public static boolean isValidExpression(final String cronExpression) {
		try {
			new CronExpression(cronExpression);
		}
		catch (final ParseException pe) {
			return false;
		}
		return true;
	}
@Test
	void isValidExpression() {
		assertThat(CronExpression.isValidExpression("0 0 0 * * ?")).isEqualTo(true);
		assertThat(CronExpression.isValidExpression("0 */5 * * * ?")).isEqualTo(true);
		assertThat(CronExpression.isValidExpression("0 0 8 1 JAN ?")).isEqualTo(true);
		assertThat(CronExpression.isValidExpression("0 0 8 ? 10 THU")).isEqualTo(true);
		assertThat(CronExpression.isValidExpression("0 0 8 ? 10 THU-SAT")).isEqualTo(true);
		assertThat(CronExpression.isValidExpression("0 0 8 ? 10 FRI#1")).isEqualTo(true);
		assertThat(CronExpression.isValidExpression("0 0 8 ? 10 FRI#5")).isEqualTo(true);
		// false
		assertThat(CronExpression.isValidExpression("0 0 8 1 JAW ?")).isEqualTo(false);
		assertThat(CronExpression.isValidExpression("0 0 8 ? 10 THP-SAT")).isEqualTo(false);
		assertThat(CronExpression.isValidExpression("0 0 8 ? 10 FRI#0")).isEqualTo(false);
		assertThat(CronExpression.isValidExpression("0 0 8 ? 10 FRI#6")).isEqualTo(false);
	}