@Test
  public void testRootDirectory() {
    Directory file = Directory.createRoot(0, fileTimeSource.now(), Name.simple("/"));
    assertThat(file.isRootDirectory()).isTrue();

    Directory otherFile = Directory.createRoot(1, fileTimeSource.now(), Name.simple("$"));
    assertThat(otherFile.isRootDirectory()).isTrue();
  }
Tests for {@link File}.

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