private fun generateSomeGarbageFiles() {
    val dir1 = cacheDir / "dir1"
    val dir2 = dir1 / "dir2"
    writeFile(getCleanFile("g1", 0), "A")
    writeFile(getCleanFile("g1", 1), "B")
    writeFile(getCleanFile("g2", 0), "C")
    writeFile(getCleanFile("g2", 1), "D")
    writeFile(getCleanFile("g2", 1), "D")
    writeFile(cacheDir / "otherFile0", "E")
    writeFile(dir2 / "otherFile1", "F")
  }