/*
   * Test for add(Duration rhs).
   */
  @Test(dataProvider = "duration-for-add")
  public void checkDurationAdd(String initVal, String addVal, String result) {
    Duration durationInit = datatypeFactory.newDuration(initVal);
    Duration durationAdd = datatypeFactory.newDuration(addVal);
    Duration durationResult = datatypeFactory.newDuration(result);

    assertEquals(durationInit.add(durationAdd), durationResult);
  }
  /*
   * Test for add(Duration rhs) 'rhs' is null , should throw NPE. "1 year" +
   * "-1 day" or "-1 year" + "1 day" should throw IllegalStateException
   */
  @Test(
      expectedExceptions = {NullPointerException.class, IllegalStateException.class},
      dataProvider = "duration-for-addneg")
  public void checkDurationAddNeg(String initVal, String addVal) {
    Duration durationInit = datatypeFactory.newDuration(initVal);
    Duration durationAdd = addVal == null ? null : datatypeFactory.newDuration(addVal);

    durationInit.add(durationAdd);
  }