}

  private Path tempDir;

  @Override
  protected void setUp() throws Exception {
    tempDir = Files.createTempDirectory("MoreFilesTest");
  }

  @Override
  protected void tearDown() throws Exception {
    if (tempDir != null) {
      // delete tempDir and its contents
      Files.walkFileTree(
          tempDir,
          new SimpleFileVisitor<Path>() {

      File baseDir = new File(JAVA_IO_TMPDIR.value());
      @SuppressWarnings("GoodTime") // reading system time without TimeSource
      String baseName = System.currentTimeMillis() + "-";

      for (int counter = 0; counter < TEMP_DIR_ATTEMPTS; counter++) {
        File tempDir = new File(baseDir, baseName + counter);
        if (tempDir.mkdir()) {
          return tempDir;
        }
      }

    }
    return asByteSource(file1).contentEquals(asByteSource(file2));
  }

  /**
   * Atomically creates a new directory somewhere beneath the system's temporary directory (as
   * defined by the {@code java.io.tmpdir} system property), and returns its name.
   *
   * <p>The temporary directory is created with permissions restricted to the current user or, in