/** Test that the addOrUpdate() method won't allow multiple time period classes. */
  @Test
  public void testAddOrUpdate3() {
    TimeSeries s1 = new TimeSeries("S1");
    s1.addOrUpdate(new Year(2010), 1.1);
    assertEquals(Year.class, s1.getTimePeriodClass());

    boolean pass = false;
    try {
      s1.addOrUpdate(new Month(1, 2009), 0.0);
    } catch (SeriesException e) {
      pass = true;
    }
    assertTrue(pass);
  }