public void testToStandardWeeks_months() {
        Period test = Period.months(1);
        try {
            test.toStandardWeeks();
            fail();
        } catch (UnsupportedOperationException ex) {}
        
        test = Period.months(-1);
        try {
            test.toStandardWeeks();
            fail();
        } catch (UnsupportedOperationException ex) {}
        
        test = Period.months(0);
        assertEquals(0, test.toStandardWeeks().getWeeks());
    }