@Test
public void testClear() throws IOException {

  for (int i = 0; i < 1000; i++) {
    estimator.insert(i);
  }
  estimator.clear();
  assertThat(estimator.getCount()).isZero();
  assertThat(estimator.getSampleCount()).isZero();
  assertThat(estimator.snapshot()).isNull();
}