val iterator = cache.snapshots()
    cache.close()
    assertThat(iterator.hasNext()).isFalse()
  }

  @ParameterizedTest
  @ArgumentsSource(FileSystemParamProvider::class)
  fun isClosed_uninitializedCache(parameters: Pair<FileSystem, Boolean>) {
    setUp(parameters.first, parameters.second)
    // Create an uninitialized cache.
    cache =