* This lock is used to ensure safe and correct cancellation, it ensures that a new task is
       * not scheduled while a cancel is ongoing. Also it protects the currentFuture variable to
       * ensure that it is assigned atomically with being scheduled.
       */
      private final ReentrantLock lock = new ReentrantLock();

      /** The future that represents the next execution of this task. */
      @GuardedBy("lock")

   * instance, so it can be invoked again to create multiple independent maps.
   *
   * <p>The bulk operations {@code putAll}, {@code equals}, and {@code clear} are not guaranteed to
   * be performed atomically on the returned map. Additionally, {@code size} and {@code
   * containsValue} are implemented as bulk read operations, and thus may fail to observe concurrent
   * writes.
   *

      E e;
      while (n < maxElements && (e = q.poll()) != null) {
        c.add(e);
        ++n;
      }
      return n;
    } finally {
      monitor.leave();
    }
  }

  /**
   * Atomically removes all of the elements from this queue. The queue will be empty after this call
   * returns.
   */
  @Override
  public void clear() {
    Monitor monitor = this.monitor;
    monitor.enter();
    try {

  public String toString() {
    Monitor monitor = this.monitor;
    monitor.enter();
    try {
      return super.toString();
    } finally {
      monitor.leave();
    }
  }

  /**
   * Atomically removes all of the elements from this queue. The queue will be empty after this call
   * returns.
   */
  @Override
  public void clear() {
    E[] items = this.items;
    Monitor monitor = this.monitor;

	BucketTargetsConfigUpdatedAt     time.Time
	BucketTargetsConfigMetaUpdatedAt time.Time
	// Add a new UpdatedAt field and update lastUpdate function

	// Unexported fields. Must be updated atomically.
	policyConfig           *policy.BucketPolicy
	notificationConfig     *event.Config
	lifecycleConfig        *lifecycle.Lifecycle
	objectLockConfig       *objectlock.Config
	versioningConfig       *versioning.Versioning

	}
	err = st.Results(func(r *CheckPartsResp) error {
		resp = r
		return nil
	})
	return resp, toStorageErr(err)
}

// RenameData - rename source path to destination path atomically, metadata and data file.
func (client *storageRESTClient) RenameData(ctx context.Context, srcVolume, srcPath string, fi FileInfo,
	dstVolume, dstPath string, opts RenameOptions,
) (res RenameDataResp, err error) {

      }
    }

    /**
     * Apply inbound settings and send an acknowledgement to the peer that provided them.
     *
     * We need to apply the settings and ack them atomically. This is because some HTTP/2
     * implementations (nghttp2) forbid peers from taking advantage of settings before they have
     * acknowledged! In particular, we shouldn't send frames that assume a new `initialWindowSize`

_2019-09-10_

 *  Fix: Don't lose HTTP/2 flow control bytes when incoming data races with a stream close. If this
    happened enough then eventually the connection would stall.

 *  Fix: Acknowledge and apply inbound HTTP/2 settings atomically. Previously we had a race where we
    could use new flow control capacity before acknowledging it, causing strict HTTP/2 servers to
    fail the call.

 *  Fix: Don't lose HTTP/2 flow control bytes when incoming data races with a stream close. If this
    happened enough then eventually the connection would stall.

 *  Fix: Acknowledge and apply inbound HTTP/2 settings atomically. Previously we had a race where we
    could use new flow control capacity before acknowledging it, causing strict HTTP/2 servers to
    fail the call.


## Version 4.1.1

_2019-09-05_

}

func skipAccessChecks(volume string) (ok bool) {
	return strings.HasPrefix(volume, minioMetaBucket)
}

// RenameData - rename source path to destination path atomically, metadata and data directory.
func (s *xlStorage) RenameData(ctx context.Context, srcVolume, srcPath string, fi FileInfo, dstVolume, dstPath string, opts RenameOptions) (res RenameDataResp, err error) {
	defer func() {