append(buf, "percent", () -> osProbe.getSystemCpuPercent());
        final OsStats osStats = osProbe.osStats();
        buf.append("},");
        append(buf, "load_averages", () -> osStats.getCpu().getLoadAverage());
        buf.append("},");
    }

    private void appendFesenStats(final StringBuilder buf) {
        String stats = null;
        try {

     */
    // GET /api/admin/stats
    @Execute
    public JsonResponse<ApiResult> index() {
        final HashMap<String, Object> stats = new HashMap<>();
        stats.put("jvm", getJvmObj());
        stats.put("os", getOsObj());
        stats.put("process", getProcessObj());
        stats.put("engine", getEngineObj());
        stats.put("fs", getFsObj());

   *
   * <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;

   * 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));
  }

  /**

    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());

 *             missCount}.
 *       </ul>
 *   <li>When an entry is evicted from the cache, {@code evictionCount} is incremented.
 *   <li>No stats are modified when a cache entry is invalidated or manually removed.
 *   <li>No stats are modified by operations invoked on the {@linkplain Cache#asMap asMap} view of
 *       the cache.
 * </ul>
 *

            this.stats = stats;
            return this;
        }

        @Override
        public ApiResult result() {
            return new ApiResult(this);
        }
    }

    /**
     * Represents an API response for bulk operations, containing a list of processed items.
     */
    public static class ApiBulkResponse extends ApiResponse {

    }

    CacheStats stats = cache.stats();
    assertEquals(removalListener.size(), stats.evictionCount());
    assertEquals(computeCount.get(), stats.loadSuccessCount());
    assertEquals(exceptionCount.get() + computeNullCount.get(), stats.loadExceptionCount());
    // each computed value is still in the cache, or was passed to the removal listener

    }

    CacheStats stats = cache.stats();
    assertEquals(removalListener.size(), stats.evictionCount());
    assertEquals(computeCount.get(), stats.loadSuccessCount());
    assertEquals(exceptionCount.get() + computeNullCount.get(), stats.loadExceptionCount());
    // each computed value is still in the cache, or was passed to the removal listener

        writeElastisearchJsonApi(zos, id, "cluster", "state");
        writeElastisearchJsonApi(zos, id, "cluster", "stats");
        writeElastisearchJsonApi(zos, id, "cluster", "pending_tasks");
        writeElastisearchJsonApi(zos, id, "nodes", "stats");
        writeElastisearchJsonApi(zos, id, "nodes", "_all");
        writeElastisearchJsonApi(zos, id, "nodes", "usage");