public void testFactory_standardPeriodIn_RPeriod() {
        assertEquals(0, Single.standardPeriodIn((ReadablePeriod) null, DateTimeConstants.MILLIS_PER_DAY));
        assertEquals(0, Single.standardPeriodIn(Period.ZERO, DateTimeConstants.MILLIS_PER_DAY));
        assertEquals(1, Single.standardPeriodIn(new Period(0, 0, 0, 1, 0, 0, 0, 0), DateTimeConstants.MILLIS_PER_DAY));
        assertEquals(123, Single.standardPeriodIn(Period.days(123), DateTimeConstants.MILLIS_PER_DAY));
        assertEquals(-987, Single.standardPeriodIn(Period.days(-987), DateTimeConstants.MILLIS_PER_DAY));
        assertEquals(1, Single.standardPeriodIn(Period.hours(47), DateTimeConstants.MILLIS_PER_DAY));
        assertEquals(2, Single.standardPeriodIn(Period.hours(48), DateTimeConstants.MILLIS_PER_DAY));
        assertEquals(2, Single.standardPeriodIn(Period.hours(49), DateTimeConstants.MILLIS_PER_DAY));
        assertEquals(14, Single.standardPeriodIn(Period.weeks(2), DateTimeConstants.MILLIS_PER_DAY));
        try {
            Single.standardPeriodIn(Period.months(1), DateTimeConstants.MILLIS_PER_DAY);
            fail();
        } catch (IllegalArgumentException ex) {
            // expeceted
        }
    }