for _, f := range files {
		err := os.MkdirAll(filepath.Dir(filepath.Join(base, bucket, f.name)), os.ModePerm)
		if err != nil {
			t.Fatal(err)
		}
		err = os.WriteFile(filepath.Join(base, bucket, f.name), make([]byte, f.size), os.ModePerm)
		if err != nil {
			t.Fatal(err)
		}
	}
}

// generateUsageTestFiles create nFolders * nFiles files of size bytes each.