You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: object_count_tracker_test.go
    path of file: ./repos/kubernetes/staging/src/k8s.io/apiserver/pkg/util/flowcontrol/request
    
    the code of the file until where you have to start completion: /*
Copyright 2021 The Kubernetes Authors.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed
    
func TestStorageObjectCountTrackerWithPrune(t *testing.T) {
	fakeClock := &testclock.FakePassiveClock{}
	tracker := &objectCountTracker{
		clock:  fakeClock,
		counts: map[string]*timestampedCount{},
	}

	now := time.Now()
	fakeClock.SetTime(now.Add(-61 * time.Minute))
	tracker.Set("k1", 61)
	fakeClock.SetTime(now.Add(-60 * time.Minute))
	tracker.Set("k2", 60)
	// we are going to prune keys that are stale for >= 1h
	// so the above keys are expected to be pruned and the
	// key below should not be pruned.
	mostRecent := now.Add(-59 * time.Minute)
	fakeClock.SetTime(mostRecent)
	tracker.Set("k3", 59)
	expected := map[string]*timestampedCount{
		"k3": {
			count:         59,
			lastUpdatedAt: mostRecent,
		},
	}

	fakeClock.SetTime(now)
	if err := tracker.prune(time.Hour); err != nil {
		t.Fatalf("Expected no error, but got: %v", err)
	}

	// we expect only one entry in the map, so DeepEqual should work.
	if !reflect.DeepEqual(expected, tracker.counts) {
		t.Errorf("Expected prune to remove stale entries - diff: %s", cmp.Diff(expected, tracker.counts))
	}
}