key = new Object();
    cache.refresh(key);
    checkNothingLogged();
    stats = cache.stats();
    assertThat(stats.missCount()).isEqualTo(2);
    assertThat(stats.loadSuccessCount()).isEqualTo(3);
    assertThat(stats.loadExceptionCount()).isEqualTo(0);
    assertThat(stats.hitCount()).isEqualTo(0);

    assertThat(cache.get(key)).isSameInstanceAs(key);
    stats = cache.stats();

    key = new Object();
    cache.refresh(key);
    checkNothingLogged();
    stats = cache.stats();
    assertThat(stats.missCount()).isEqualTo(2);
    assertThat(stats.loadSuccessCount()).isEqualTo(3);
    assertThat(stats.loadExceptionCount()).isEqualTo(0);
    assertThat(stats.hitCount()).isEqualTo(0);

    assertThat(cache.get(key)).isSameInstanceAs(key);
    stats = cache.stats();

    assertThat(stats.min()).isEqualTo(MEGA_STREAM_MIN);
    assertThat(stats.max()).isEqualTo(MEGA_STREAM_MAX);
  }

  public void testOfPrimitiveLongStream() {
    Stats stats = Stats.of(megaPrimitiveDoubleStream().mapToLong(x -> (long) x));
    assertThat(stats.count()).isEqualTo(MEGA_STREAM_COUNT);
    assertThat(stats.mean()).isWithin(ALLOWED_ERROR * MEGA_STREAM_COUNT).of(MEGA_STREAM_MEAN);
    assertThat(stats.populationVariance())

        // Log all available stats fields for debugging
        logger.info("Available stats fields: {}", res.keySet());

        // Verify response contains meaningful data
        assertNotNull(res, "Stats response should not be null");
        assertTrue(res.size() > 0, "Stats should contain at least some data");

        // Check for common stats fields (these may need to be adjusted based on actual implementation)

  // Stats instances:

  static final Stats EMPTY_STATS_VARARGS = Stats.of();
  static final Stats EMPTY_STATS_ITERABLE = Stats.of(ImmutableList.<Double>of());
  static final Stats ONE_VALUE_STATS = Stats.of(ONE_VALUE);
  static final Stats OTHER_ONE_VALUE_STATS = Stats.of(OTHER_ONE_VALUE);
  static final Stats TWO_VALUES_STATS = Stats.of(TWO_VALUES);

    stats = cache.stats();
    assertThat(stats.requestCount()).isEqualTo(3);
    assertThat(stats.hitCount()).isEqualTo(1);
    assertThat(stats.hitRate()).isEqualTo(1.0 / 3);
    assertThat(stats.missCount()).isEqualTo(2);
    assertThat(stats.missRate()).isEqualTo(2.0 / 3);
    assertThat(stats.loadCount()).isEqualTo(2);
    assertThat(stats.totalLoadTime()).isAtLeast(totalLoadTime);
    totalLoadTime = stats.totalLoadTime();

    stats = cache.stats();
    assertThat(stats.requestCount()).isEqualTo(3);
    assertThat(stats.hitCount()).isEqualTo(1);
    assertThat(stats.hitRate()).isEqualTo(1.0 / 3);
    assertThat(stats.missCount()).isEqualTo(2);
    assertThat(stats.missRate()).isEqualTo(2.0 / 3);
    assertThat(stats.loadCount()).isEqualTo(2);
    assertThat(stats.totalLoadTime()).isAtLeast(totalLoadTime);
    totalLoadTime = stats.totalLoadTime();

  // Stats instances:

  static final Stats EMPTY_STATS_VARARGS = Stats.of();
  static final Stats EMPTY_STATS_ITERABLE = Stats.of(ImmutableList.<Double>of());
  static final Stats ONE_VALUE_STATS = Stats.of(ONE_VALUE);
  static final Stats OTHER_ONE_VALUE_STATS = Stats.of(OTHER_ONE_VALUE);
  static final Stats TWO_VALUES_STATS = Stats.of(TWO_VALUES);

/**
 * Tests for {@link StatsAccumulator}. This tests the stats methods for instances built with {@link
 * StatsAccumulator#add} and {@link StatsAccumulator#addAll}, and various error cases of the {@link
 * StatsAccumulator#add} and {@link StatsAccumulator#addAll} methods. For tests of the {@link
 * StatsAccumulator#snapshot} method which returns {@link Stats} instances, see {@link StatsTest}.
 *
 * @author Pete Gillin
 */

      PairedStats stats = createPairedStatsOf(values.asIterable(), OTHER_MANY_VALUES);
      LinearTransformation fit = stats.leastSquaresFit();
      if (values.hasAnyNonFinite()) {
        assertLinearTransformationNaN(fit);
      } else {
        assertDiagonalLinearTransformation(
            fit,
            stats.xStats().mean(),
            stats.yStats().mean(),