return (totalLoadCount == 0) ? 0.0 : (double) loadExceptionCount / totalLoadCount;
  }

  /**
   * Returns the total number of nanoseconds the cache has spent loading new values. This can be
   * used to calculate the miss penalty. This value is increased every time {@code loadSuccessCount}
   * or {@code loadExceptionCount} is incremented.
   */
  @SuppressWarnings("GoodTime") // should return a java.time.Duration

    return (totalLoadCount == 0) ? 0.0 : (double) loadExceptionCount / totalLoadCount;
  }

  /**
   * Returns the total number of nanoseconds the cache has spent loading new values. This can be
   * used to calculate the miss penalty. This value is increased every time {@code loadSuccessCount}
   * or {@code loadExceptionCount} is incremented.
   */
  @SuppressWarnings("GoodTime") // should return a java.time.Duration

   * reason that this is warmupPeriod/2 is to maintain the behavior of the original implementation
   * where coldFactor was hard coded as 3.)
   *
   * <p>It remains to calculate thresholdsPermits and maxPermits.
   *
   * <ul>
   *   <li>The time to go from thresholdPermits to 0 is equal to the integral of the function

			return nil, ObjectInfo{}, err
		}
		b, err := io.ReadAll(gr)
		gr.Close()
		if err != nil {
			return nil, ObjectInfo{}, err
		}
		if size > len(b) {
			size = len(b)
		}

		// Calculate the object real size if encrypted
		if _, ok := crypto.IsEncrypted(gr.ObjInfo.UserDefined); ok {
			objSize, err = gr.ObjInfo.DecryptedSize()
			if err != nil {
				return nil, ObjectInfo{}, err
			}
		} else {

	defer cancel()

	if target.args.Format == event.NamespaceFormat {
		objectName, err := url.QueryUnescape(eventData.S3.Object.Key)
		if err != nil {
			return err
		}

		// Calculate a hash of the key for the id of the ES document.
		// Id's are limited to 512 bytes in V7+, so we need to do this.
		var keyHash string
		{
			key := eventData.S3.Bucket.Name + "/" + objectName

	// If not set the client will not keep track of health.
	// Calling this returns true or false if the target
	// is online or offline.
	HealthCheckFn func() bool

	// HealthCheckRetryUnit will be used to calculate the exponential
	// backoff when trying to reconnect to an offline node
	HealthCheckReconnectUnit time.Duration

	// HealthCheckTimeout determines timeout for each call.
	HealthCheckTimeout time.Duration

var ignoredStreamingHeaders = map[string]bool{
	"Authorization": true,
	"Content-Type":  true,
	"Content-Md5":   true,
	"User-Agent":    true,
}

// calculateSignedChunkLength - calculates the length of chunk metadata
func calculateSignedChunkLength(chunkDataSize int64) int64 {
	return int64(len(fmt.Sprintf("%x", chunkDataSize))) +
		17 + // ";chunk-signature="

### **4.1 Spark Pi**

Test the Spark installation by running the following compute intensive example, which calculates pi by “throwing darts” at a circle. The program generates points in the unit square ((0,0) to (1,1)) and counts how many points fall within the unit circle within the square. The result approximates pi.

     * CRC(x ^ y) == CRC(x) ^ CRC(y).  The approach we take is to break the message as follows,
     * with each letter representing a 4-byte word: ABCDABCDABCDABCD... and to calculate
     * CRC(A000A000A000...), CRC(0B000B000B...), CRC(00C000C000C...), CRC(000D000D000D...)
     * and then to XOR them together.  The STRIDE_TABLE enables us to hash an int followed by 12

   */
  public double max() {
    checkState(count != 0);
    return max;
  }

  double sumOfSquaresOfDeltas() {
    return sumOfSquaresOfDeltas;
  }

  /**
   * Calculates the new value for the accumulated mean when a value is added, in the case where at
   * least one of the previous mean and the value is non-finite.
   */