title: Do I have to clean my Jimfs FileSystem after each test?
body: <p>I'm using Jimfs in my tests like this:</p>
  
  <pre><code>public class FooTest {
    private FileSystem fs = Jimfs.newFileSystem(Configuration.unix());
    private List&lt;Path&gt; paths = new ArrayList&lt;&gt;();
    private Path getPath(String first, String... more) {
      Path path = fs.getPath(first, more);
      paths.add(path);
      return path;
    }
    @After public void cleanPaths() {
      for (Path path: paths) {
        Files.walkFileTree(path, FileVisitors.DELETE);
      }
    }
    @Test public void bar() {
      Path baz = getPath("baz");
      // test using baz
    }
  }
  </code></pre>
  
  <p>Now, we know that Jimfs is in memory. Do I really need to clean up the paths I created or can I just remove the <code>@After</code> method (and its associated mechanism)?</p>
  
  <p>I clearly think it's the basic need why jimfs was created, but well... I'm adapting existing code and I suddenly became confused about this.</p>