public void testFactory_standardWeeksIn_RPeriod() {
        assertEquals(0, Weeks.standardWeeksIn((ReadablePeriod) null).getWeeks());
        assertEquals(0, Weeks.standardWeeksIn(Period.ZERO).getWeeks());
        assertEquals(1, Weeks.standardWeeksIn(new Period(0, 0, 1, 0, 0, 0, 0, 0)).getWeeks());
        assertEquals(123, Weeks.standardWeeksIn(Period.weeks(123)).getWeeks());
        assertEquals(-987, Weeks.standardWeeksIn(Period.weeks(-987)).getWeeks());
        assertEquals(1, Weeks.standardWeeksIn(Period.days(13)).getWeeks());
        assertEquals(2, Weeks.standardWeeksIn(Period.days(14)).getWeeks());
        assertEquals(2, Weeks.standardWeeksIn(Period.days(15)).getWeeks());
        try {
            Weeks.standardWeeksIn(Period.months(1));
            fail();
        } catch (IllegalArgumentException ex) {
            // expeceted
        }
    }