@Nonnull
  @Override
  public CpcSketch getResult() {
    return unionAll();
  }
@Test
  public void testAccumulatorMerge() {
    CpcSketch sketch1 = new CpcSketch(_lgNominalEntries);
    IntStream.range(0, 1000).forEach(sketch1::update);
    CpcSketch sketch2 = new CpcSketch(_lgNominalEntries);
    IntStream.range(1000, 2000).forEach(sketch2::update);

    CpcSketchAccumulator accumulator1 = new CpcSketchAccumulator(_lgNominalEntries, 3);
    accumulator1.apply(sketch1);
    CpcSketchAccumulator accumulator2 = new CpcSketchAccumulator(_lgNominalEntries, 3);
    accumulator2.apply(sketch2);
    accumulator1.merge(accumulator2);

    Assert.assertEquals(accumulator1.getResult().getEstimate(), sketch1.getEstimate() + sketch2.getEstimate(),
        _epsilon);
  }