@Before
  public void setUp() {
    fs = (JimfsFileSystem) Jimfs.newFileSystem(Configuration.unix());
    watcher =
        new PollingWatchService(
            fs.getDefaultView(),
            fs.getPathService(),
            new FileSystemState(new FakeFileTimeSource(), Runnables.doNothing()),
            4,
            MILLISECONDS);
  }
Tests for {@link PollingWatchService}.

@author Colin Decker
jimfs/src/test/java/com/google/common/jimfs/PollingWatchServiceTest.java