public void testSePeriodAfterStart_RI2() {
   MutableInterval test = new MutableInterval(TEST_TIME1, TEST_TIME2);
   try {
     test.setPeriodAfterStart(new Period(-1L));
     fail();
   } catch (IllegalArgumentException ex) {
   }
 }
 public void testSetPeriodAfterStart_RI3() {
   MutableInterval test = new MutableInterval(TEST_TIME1, TEST_TIME2);
   test.setPeriodAfterStart(null);
   assertEquals(TEST_TIME1, test.getStartMillis());
   assertEquals(TEST_TIME1, test.getEndMillis());
 }