### Question:
FileUtil { public static boolean deleteTempFiles(final File workFolder) { if (workFolder.isDirectory()) { File[] entries = workFolder.listFiles(); for (int i = 0; i < entries.length; i++) { File current = entries[i]; boolean deleteTempFiles = deleteTempFiles(current); if (!deleteTempFiles) { return false; } else { logger.info("Deleted: " + current); } } return workFolder.delete(); } return workFolder.delete(); } private  FileUtil(); static File getSystemTempFolder(); static File getTmpFile(final String name, final String suffix); static File getTmpFile(final byte[] data, final String name,
            final String suffix); static boolean deleteTempFiles(final File workFolder); static void close(final Closeable out); static boolean mkdir(final File file); static boolean mkdirs(final File file); static String makePath(String... parts); static final String JAVA_TMP; }### Answer:
@Test public void testDeleteTempFiles() { File temp = new File(JAVA_TMP, "gwg-tmp-store"); if (!temp.exists()) FileUtil.getTmpFile("prueba", "tmp"); byte[] data = new byte[1]; data[0]=(byte)0xFF; FileUtil.getTmpFile(data, "prueba", "tmp"); FileUtil.deleteTempFiles(temp); }