assertStatsApproxEqual(OTHER_ONE_VALUE_STATS, oneValueAccumulator.yStats());
    assertStatsApproxEqual(
        OTHER_ONE_VALUE_STATS, oneValueAccumulatorByAddAllEmptyPairedStats.yStats());
    assertStatsApproxEqual(OTHER_TWO_VALUES_STATS, twoValuesAccumulator.yStats());
    assertStatsApproxEqual(
        OTHER_TWO_VALUES_STATS, twoValuesAccumulatorByAddAllPartitionedPairedStats.yStats());

   *
   * <ul>
   *   <li>Both {@code xStats} and {@code yStats} must have the same {@code count}.
   *   <li>If that {@code count} is 1, {@code sumOfProductsOfDeltas} must be exactly 0.0.
   *   <li>If that {@code count} is more than 1, {@code sumOfProductsOfDeltas} must be finite.
   * </ul>
   */
  PairedStats(Stats xStats, Stats yStats, double sumOfProductsOfDeltas) {
    this.xStats = xStats;
    this.yStats = yStats;

              + (values.xStats().mean() - xStats.mean())
                  * (values.yStats().mean() - yStats.mean())
                  * values.count();
    }
    yStats.addAll(values.yStats());
  }

  /** Returns an immutable snapshot of the current statistics. */
  public PairedStats snapshot() {
    return new PairedStats(xStats.snapshot(), yStats.snapshot(), sumOfProductsOfDeltas);
  }

   * versions.
   */
  public static Stats fromByteArray(byte[] byteArray) {
    checkNotNull(byteArray);
    checkArgument(
        byteArray.length == BYTES,
        "Expected Stats.BYTES = %s remaining , got %s",
        BYTES,
        byteArray.length);
    return readFrom(ByteBuffer.wrap(byteArray).order(ByteOrder.LITTLE_ENDIAN));
  }

  /**

    assertEquals(2, stats.requestCount());
    assertEquals(1, stats.hitCount());
    assertThat(stats.hitRate()).isEqualTo(1.0 / 2);
    assertEquals(1, stats.missCount());
    assertThat(stats.missRate()).isEqualTo(1.0 / 2);
    assertEquals(1, stats.loadCount());
    assertEquals(0, stats.evictionCount());

    Object two = new Object();
    cache.getUnchecked(two);
    stats = cache.stats();
    assertEquals(3, stats.requestCount());

        assertEquals(SimpleCircuitBreaker.State.CLOSED, circuitBreaker.getState());

        SimpleCircuitBreaker.Statistics stats = circuitBreaker.getStatistics();
        assertEquals(1, stats.totalCalls);
        assertEquals(1, stats.totalSuccesses);
        assertEquals(0, stats.totalFailures);
        assertEquals(1.0, stats.successRate);
    }

    @Test
    @DisplayName("Test circuit opens after failure threshold")

    stats = cache.stats();
    assertEquals(2, stats.missCount());
    assertEquals(3, stats.loadSuccessCount());
    assertEquals(0, stats.loadExceptionCount());
    assertEquals(0, stats.hitCount());

    assertSame(key, cache.get(key));
    stats = cache.stats();
    assertEquals(2, stats.missCount());
    assertEquals(3, stats.loadSuccessCount());
    assertEquals(0, stats.loadExceptionCount());

        Map<EventType, Long> stats = logger.getStatistics();
        assertEquals(Long.valueOf(1), stats.get(EventType.AUTHENTICATION_SUCCESS), "Should have 1 authentication success event");
        assertEquals(Long.valueOf(1), stats.get(EventType.AUTHENTICATION_FAILURE), "Should have 1 authentication failure event");
        assertEquals(Long.valueOf(1), stats.get(EventType.FILE_ACCESS), "Should have 1 file access event");

    StatsCounter counter = new SimpleStatsCounter();
    CacheStats stats = counter.snapshot();
    assertEquals(0, stats.requestCount());
    assertEquals(0, stats.hitCount());
    assertThat(stats.hitRate()).isEqualTo(1.0);
    assertEquals(0, stats.missCount());
    assertThat(stats.missRate()).isEqualTo(0.0);
    assertEquals(0, stats.loadSuccessCount());
    assertEquals(0, stats.loadExceptionCount());
    assertEquals(0, stats.loadCount());

        resourceManager.markClosed(id1);

        Map<String, Object> stats = resourceManager.getStatistics();

        assertNotNull(stats);
        assertTrue((long) stats.get("totalAllocated") >= 2);
        assertTrue((long) stats.get("totalReleased") >= 1);
        assertNotNull(stats.get("activeResources"));
        assertNotNull(stats.get("closedResources"));
    }

    @Test