@Test
public void testFileScan() throws Exception {

    File file = new File("build");
    FileScanner fileScanner = new FileScanner(file,10);
    AtomicInteger counter = new AtomicInteger();
    counter.getAndSet(0);
    Listener listener = event -> counter.getAndIncrement();
    fileScanner.registerListener(listener);
    Thread f = new Thread(fileScanner);
    f.start();
    TimeUnit.MILLISECONDS.sleep(50);
    FileWriter myWriter = new FileWriter("build/test.txt");
    myWriter.write("test");
    myWriter.close();
    TimeUnit.MILLISECONDS.sleep(50);
    FileUtils.deleteDir(new File("build/test.txt"));
    TimeUnit.MILLISECONDS.sleep(50);
    assertEquals(2,counter.get());
}