* single element: that file.
   *
   * <p>Example: {@code Files.fileTraverser().depthFirstPreOrder(new File("/"))} may return files
   * with the following paths: {@code ["/", "/etc", "/etc/config.txt", "/etc/fonts", "/home",
   * "/home/alice", ...]}
   *
   * @since 23.5
   */
  public static Traverser<File> fileTraverser() {
    return Traverser.forTree(FILE_TREE);
  }

 * of the code may not be readable by older versions of the code (e.g., a serialized Bloom filter
 * generated today may <i>not</i> be readable by a binary that was compiled 6 months ago).
 *
 * <p>As of Guava 23.0, this class is thread-safe and lock-free. It internally uses atomics and
 * compare-and-swap to ensure correctness when multiple threads are used to access it.
 *

    public static final String LABELS_facet_timestamp_1year = "{labels.facet_timestamp_1year}";

    /** The key of the message: Past 3 Months */
    public static final String LABELS_facet_timestamp_3month = "{labels.facet_timestamp_3month}";

    /** The key of the message: Past 6 Months */
    public static final String LABELS_facet_timestamp_6month = "{labels.facet_timestamp_6month}";

    /** The key of the message: Past 2 Years */