public static List<Period> getMailPeriods() {
		final List<Period> mailPeriods;
		if (Parameter.MAIL_PERIODS.getValue() == null) {
			mailPeriods = Collections.singletonList(Period.SEMAINE);
		} else {
			final String mailPeriodsParameter = Parameter.MAIL_PERIODS.getValue();
			mailPeriods = new ArrayList<>();
			for (final String mailPeriod : mailPeriodsParameter.split(",")) {
				mailPeriods.add(Period.valueOfByMailCode(mailPeriod));
			}
		}
		return mailPeriods;
	}
@Test
	public void testGetMailPeriod() {
		for (final Period period : Period.values()) {
			assertNotNull("getMailCode", period.getMailCode());
			assertEquals("valueOfByMailCode", period,
					Period.valueOfByMailCode(period.getMailCode()));
		}
		try {
			Period.valueOfByMailCode("unknown");
		} catch (final IllegalArgumentException e) {
			assertNotNull("ok", e);
		}

		assertEquals("getMailPeriods", Collections.singletonList(Period.SEMAINE),
				MailReport.getMailPeriods());
		setProperty(Parameter.MAIL_PERIODS, Period.JOUR.getMailCode());
		assertEquals("getMailPeriods", Collections.singletonList(Period.JOUR),
				MailReport.getMailPeriods());
	}