map.put(new Object(), i);
    }
    assertEquals(ITERATIONS, map.size());

    map.clear();
    assertEquals(0, map.size());
    assertTrue(map.isEmpty());
  }

  public void testSum() {
    AtomicLongMap<Object> map = AtomicLongMap.create();
    long sum = 0;
    for (int i = 0; i < ITERATIONS; i++) {
      map.put(new Object(), i);
      sum += i;
    }

        .of(LONG_MANY_VALUES_MEAN);
    assertThat(longManyValuesAccumulatorByAddAllVarargs.mean())
        .isWithin(ALLOWED_ERROR * LONG_MANY_VALUES_MEAN)
        .of(LONG_MANY_VALUES_MEAN);
  }

  public void testSum() {
    assertThat(emptyAccumulator.sum()).isEqualTo(0.0);
    assertThat(emptyAccumulatorByAddAllEmptyIterable.sum()).isEqualTo(0.0);
    assertThat(emptyAccumulatorByAddAllEmptyStats.sum()).isEqualTo(0.0);