public virtual void test_isRegular_null() { SchedulePeriod test = SchedulePeriod.of(JUN_16, JUL_18); assertThrowsIllegalArg(() => test.isRegular(null, DAY_18)); assertThrowsIllegalArg(() => test.isRegular(P1M, null)); assertThrowsIllegalArg(() => test.isRegular(null, null)); }