@Test
 public void test20090720() {
   DescriptiveStatistics descriptiveStatistics = new DescriptiveStatistics(100);
   for (int i = 0; i < 161; i++) {
     descriptiveStatistics.addValue(1.2);
   }
   descriptiveStatistics.clear();
   descriptiveStatistics.addValue(1.2);
   Assert.assertEquals(1, descriptiveStatistics.getN());
 }
  public void checkremoval(
      DescriptiveStatistics dstat, int wsize, double mean1, double mean2, double mean3) {

    dstat.setWindowSize(wsize);
    dstat.clear();

    for (int i = 1; i <= 6; ++i) {
      dstat.addValue(i);
    }

    Assert.assertTrue(Precision.equalsIncludingNaN(mean1, dstat.getMean()));
    dstat.replaceMostRecentValue(0);
    Assert.assertTrue(Precision.equalsIncludingNaN(mean2, dstat.getMean()));
    dstat.removeMostRecentValue();
    Assert.assertTrue(Precision.equalsIncludingNaN(mean3, dstat.getMean()));
  }