testCancel := func(fn func()) {
		t.Helper()
		defer timeout(5 * time.Second)()
		rb.Reset()
		done := make(chan struct{})
		go func() {
			defer close(done)
			time.Sleep(10 * time.Millisecond)
			fn()
		}()
		rb.CloseWithError(errors.New("test error"))
		<-done

		rb.Reset()
		done = make(chan struct{})
		go func() {
			defer close(done)
			fn()
		}()
		time.Sleep(10 * time.Millisecond)

	// This call is not implemented for remote client on purpose.
	// healing tracker is always for local disks.
	return nil
}

func (client *storageRESTClient) NSScanner(ctx context.Context, cache dataUsageCache, updates chan<- dataUsageEntry, scanMode madmin.HealScanMode, _ func() bool) (dataUsageCache, error) {
	defer xioutil.SafeClose(updates)

	st, err := storageNSScannerRPC.Call(ctx, client.gridConn, &nsScannerOptions{

}

// Describe - implements prometheus.Collector interface.
func (mg *MetricsGroup) Describe(ch chan<- *prometheus.Desc) {
	for _, desc := range mg.Descriptors {
		ch <- desc.toPromDesc(mg.CollectorPath.metricPrefix(), mg.ExtraLabels)
	}
}

// Collect - implements prometheus.Collector interface.
func (mg *MetricsGroup) Collect(ch chan<- prometheus.Metric) {
	metricValues := newMetricValues(mg.descriptorMap)

	var err error

type ObjectLayer interface {
	// Locking operations on object.
	NewNSLock(bucket string, objects ...string) RWLocker

	// Storage operations.
	Shutdown(context.Context) error
	NSScanner(ctx context.Context, updates chan<- DataUsageInfo, wantCycle uint32, scanMode madmin.HealScanMode) error
	BackendInfo() madmin.BackendInfo
	Legacy() bool // Only returns true for deployments which use CRCMOD as its object distribution algorithm.

import junit.framework.TestCase;
import junit.framework.TestSuite;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tests for {@link ForwardingMultiset}.
 *
 * @author Hayward Chan
 * @author Louis Wasserman
 */
public class ForwardingMultisetTest extends TestCase {

  static final class StandardImplForwardingMultiset<T> extends ForwardingMultiset<T> {
    private final Multiset<T> backingCollection;

import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * GWT emulation of {@link com.google.common.collect.ImmutableBiMap}.
 *
 * @author Hayward Chan
 */
@ElementTypesAreNonnullByDefault
public abstract class ImmutableBiMap<K, V> extends ForwardingImmutableMap<K, V>
    implements BiMap<K, V> {
  public static <T extends @Nullable Object, K, V>

   *     </ul>
   */
  @Deprecated
  public static HashFunction sha1() {
    return Sha1Holder.SHA_1;
  }

  private static class Sha1Holder {
    static final HashFunction SHA_1 = new MessageDigestHashFunction("SHA-1", "Hashing.sha1()");
  }

  /** Returns a hash function implementing the SHA-256 algorithm (256 hash bits). */
  public static HashFunction sha256() {

// constant. See the Go language specification's "Length and capacity" section for
// details.
func cap(v Type) int

// The make built-in function allocates and initializes an object of type
// slice, map, or chan (only). Like new, the first argument is a type, not a
// value. Unlike new, make's return type is the same as the type of its
// argument, not a pointer to it. The specification of the result depends on
// the type:
//

		return fmt.Errorf("cannot update resource %s, got status %s", scope.Name, resp.Status)
	}
	return nil
}

func (c *ControlzClient) PutScopes(scopes []*ScopeInfo) error {
	ch := make(chan struct {
		err       error
		scopeName string
	}, len(scopes))
	var wg sync.WaitGroup
	for _, scope := range scopes {
		wg.Add(1)
		go func(si *ScopeInfo) {
			defer wg.Done()
			err := c.PutScope(si)

A non-current object version is a version which is not the latest for a given object. It is possible to set up an automatic removal of non-current versions when a version becomes older than a given number of days.

e.g., To scan objects stored under `user-uploads/` prefix and remove versions older than one year.

```
{
    "Rules": [
        {
            "ID": "Removing all old versions",
            "Filter": {