ch := make(chan itemOrErr[string])

	go func() {
		defer xioutil.SafeClose(ch)

		// Allocate new results channel to receive ObjectInfo.
		objInfoCh := make(chan itemOrErr[ObjectInfo])

		if err := objAPI.Walk(ctx, minioMetaBucket, pathPrefix, objInfoCh, WalkOptions{}); err != nil {
			select {
			case ch <- itemOrErr[string]{Err: err}:
			case <-ctx.Done():

	}

	wk, err := workers.New(workerSize)
	if err != nil {
		// invalid worker size.
		return err
	}

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

	results := make(chan itemOrErr[ObjectInfo], workerSize)
	if err := api.Walk(ctx, r.Bucket, r.Prefix, results, WalkOptions{
		Marker:       lastObject,
		LatestOnly:   false, // we need to visit all versions of the object to implement purge: retainVersions