* 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));
  }

  /**

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

    Object one = new Object();
    Object two = new Object();

    assertNull(cache.getIfPresent(one));
    stats = cache.stats();
    assertEquals(1, stats.missCount());

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

    Object one = new Object();
    Object two = new Object();

    assertNull(cache.getIfPresent(one));
    stats = cache.stats();
    assertEquals(1, stats.missCount());

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

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

          .doubleValue();

  // 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);

  public void testEmpty() {
    CacheStats stats = new CacheStats(0, 0, 0, 0, 0, 0);
    assertEquals(0, stats.requestCount());
    assertEquals(0, stats.hitCount());
    assertEquals(1.0, stats.hitRate());
    assertEquals(0, stats.missCount());
    assertEquals(0.0, stats.missRate());
    assertEquals(0, stats.loadSuccessCount());
    assertEquals(0, stats.loadExceptionCount());
    assertEquals(0.0, stats.loadExceptionRate());

    // Add two elements and invalidate them.
    cache.put(1, 4);
    cache.put(2, 8);

    cache.invalidateAll();

    assertEquals(2, stats[0]);
    assertEquals(2, stats[1]);
    assertEquals(4, stats[2]);
    assertEquals(3, stats[3]);
  }

  public void testPutAll() {
    Cache<Integer, Integer> cache = CacheBuilder.newBuilder().build();

    // Add two elements and invalidate them.
    cache.put(1, 4);
    cache.put(2, 8);

    cache.invalidateAll();

    assertEquals(2, stats[0]);
    assertEquals(2, stats[1]);
    assertEquals(4, stats[2]);
    assertEquals(3, stats[3]);
  }

  public void testPutAll() {
    Cache<Integer, Integer> cache = CacheBuilder.newBuilder().build();

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

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

        // this getUnchecked() call shouldn't be a cache miss; verified below
        assertEquals(entry.getValue(), cache.getUnchecked(entry.getKey()));
      }
      assertEquals(WARMUP_SIZE, cache.stats().missCount());
      checkValidState(cache);
    }
  }

  public void testPut_populated() {
    for (LoadingCache<Object, Object> cache : caches()) {
      // don't let the entries get GCed