@Test
public void testEmptyReservoir()
{

  MergeableExponentiallyDecayingReservoir res = new MergeableExponentiallyDecayingReservoir(10, 0.015);
  // add NO data
  double[] dataValues = res.getUnsortedValues();
  assertEquals("expected empty dataValues array", 0, dataValues.length);
  double result = StatUtils.percentile(dataValues, 50.0);
  assertEquals("expected NaN for 50th percentile of empty array", Double.NaN, result);
  result = StatUtils.max(dataValues);
  assertEquals("expected NaN for max of empty array", Double.NaN, result);
}