oos.writeObject(map);
    oos.flush();

    int mapSize = bytes.size();
    oos.writeObject(keySet);
    oos.writeObject(values);
    oos.close();

    int finalSize = bytes.size();

    assertThat(finalSize - mapSize).isLessThan(100);
  }

  public void testEquals() {
    new EqualsTester()
        .addEqualityGroup(
            ImmutableMap.of(),

    return toStringHelper(this).add("state", state.get()).addValue(future).toString();
  }

  @SuppressWarnings("removal") // b/260137033
  @Override
  protected void finalize() {
    if (state.get().equals(OPEN)) {
      logger.get().log(SEVERE, "Uh oh! An open ClosingFuture has leaked and will close: {0}", this);
      FluentFuture<V> unused = finishToFuture();
    }
  }