public void testFactory_standardSecondsIn_RPeriod() {
        assertEquals(0, Seconds.standardSecondsIn((ReadablePeriod) null).getSeconds());
        assertEquals(0, Seconds.standardSecondsIn(Period.ZERO).getSeconds());
        assertEquals(1, Seconds.standardSecondsIn(new Period(0, 0, 0, 0, 0, 0, 1, 0)).getSeconds());
        assertEquals(123, Seconds.standardSecondsIn(Period.seconds(123)).getSeconds());
        assertEquals(-987, Seconds.standardSecondsIn(Period.seconds(-987)).getSeconds());
        assertEquals(2 * 24 * 60 * 60, Seconds.standardSecondsIn(Period.days(2)).getSeconds());
        try {
            Seconds.standardSecondsIn(Period.months(1));
            fail();
        } catch (IllegalArgumentException ex) {
            // expeceted
        }
    }