### Question:
ParseFileController { public void clearCache() { File[] files = cachePath.listFiles(); if (files == null) { return; } for (File file : files) { ParseFileUtils.deleteQuietly(file); } } ParseFileController(ParseHttpClient restClient, File cachePath); File getCacheFile(ParseFile.State state); boolean isDataAvailable(ParseFile.State state); void clearCache(); Task<ParseFile.State> saveAsync(
      final ParseFile.State state,
      final byte[] data,
      String sessionToken,
      ProgressCallback uploadProgressCallback,
      Task<Void> cancellationToken); Task<ParseFile.State> saveAsync(
      final ParseFile.State state,
      final File file,
      String sessionToken,
      ProgressCallback uploadProgressCallback,
      Task<Void> cancellationToken); Task<File> fetchAsync(
      final ParseFile.State state,
      @SuppressWarnings("UnusedParameters") String sessionToken,
      final ProgressCallback downloadProgressCallback,
      final Task<Void> cancellationToken);  }### Answer:
@Test public void testClearCache() throws IOException { File root = temporaryFolder.getRoot(); ParseFileController controller = new ParseFileController(null, root); File file1 = temporaryFolder.newFile("test_file_1"); File file2 = temporaryFolder.newFile("test_file_2"); controller.clearCache(); assertFalse(file1.exists()); assertFalse(file2.exists()); }