if compactInterval != 0 {
		go compactor(ctx, client, compactInterval)
	}
}

// compactor periodically compacts historical versions of keys in etcd.
// It will compact keys with versions older than given interval.
// In other words, after compaction, it will only contain keys set during last interval.
// Any API call for the older versions of keys will return error.

		}

		if foundBefore {
			// replace compactor
			compactor.cancel()
			compactor.client.Close()
		} else {
			// start new compactor
			compactor = &runningCompactor{}
			compactors[key] = compactor
		}

		ctx, cancel := context.WithCancel(context.Background())

		compactor.interval = interval
		compactor.cancel = cancel
		compactor.client = compactorClient

	curTime, _, err := compact(ctx, client, 0, putResp.Header.Revision)
	if err != nil {
		t.Fatalf("compact failed: %v", err)
	}
	if curTime != 1 {
		t.Errorf("Expect current logical time = 1, get = %v", curTime)
	}

	// Compact again with the same parameters. It won't do compaction but return the latest compact time.
	curTime2, _, err := compact(ctx, client, 0, putResp.Header.Revision)
	if err != nil {
		t.Fatalf("compact failed: %v", err)
	}

)

// Comparator diffs between a config dump from Istiod and one from Envoy
type Comparator struct {
	envoy, istiod *configdump.Wrapper
	w             io.Writer
	context       int
	location      string
}

// NewComparator is a comparator constructor
func NewComparator(w io.Writer, istiodResponses map[string][]byte, envoyResponse []byte) (*Comparator, error) {
	c := &Comparator{}

// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

// Package compact defines a compact representation of language tags.
//
// Common language tags (at least all for which locale information is defined
// in CLDR) are assigned a unique index. Each Tag is associated with such an
// ID for selecting language-related resources (such as translations) as well

// Copyright 2018 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package language

// CompactCoreInfo is a compact integer with the three core tags encoded.
type CompactCoreInfo uint32

// GetCompactCore generates a uint32 value that is guaranteed to be unique for
// different language, region, and script values.

	}

	if !into.Compacted && f.newCache.Info.Name != folder.name {
		flat := f.newCache.sizeRecursive(thisHash.Key())
		flat.Compacted = true
		var compact bool
		if flat.Objects < dataScannerCompactLeastObject {
			compact = true
		} else {
			// Compact if we only have objects as children...
			compact = true
			for k := range into.Children {

* Inter pod topological affinity and anti-affinity implementation ([#22985](https://github.com/kubernetes/kubernetes/pull/22985), [@kevin-wangzefeng](https://github.com/kevin-wangzefeng))
* start etcd compactor in background ([#25010](https://github.com/kubernetes/kubernetes/pull/25010), [@hongchaodeng](https://github.com/hongchaodeng))

		c.Lock()
		defer c.Unlock()

		if c.watchCache.resourceVersion < rv {
			t.Fatalf("Can't compact into a future version: %v", resourceVersion)
		}

		if len(c.watchers.allWatchers) > 0 || len(c.watchers.valueWatchers) > 0 {
			// We could consider terminating those watchers, but given
			// watchcache doesn't really support compaction and we don't
			// exercise it in tests, we just throw an error here.

    }


    /**
     * Returns a sorted copy of the provided collection of things. Uses the provided comparator to sort.
     */
    public static <T> List<T> sort(Iterable<? extends T> things, Comparator<? super T> comparator) {
        List<T> copy = toMutableList(things);
        Collections.sort(copy, comparator);
        return copy;
    }

    /**