return viewer.preOrderTraversal(root);
      }
    },
    POST_ORDER {
      @Override
      <T> Iterable<T> view(T root, TreeTraverser<T> viewer) {
        return viewer.postOrderTraversal(root);
      }
    },
    BREADTH_FIRST {
      @Override
      <T> Iterable<T> view(T root, TreeTraverser<T> viewer) {
        return viewer.breadthFirstTraversal(root);
      }
    };

  }

  public void testPreOrder() {
    assertThat(iterationOrder(ADAPTER.preOrderTraversal(h))).isEqualTo("hdabcegf");
  }

  public void testPostOrder() {
    assertThat(iterationOrder(ADAPTER.postOrderTraversal(h))).isEqualTo("abcdefgh");
  }

  public void testBreadthOrder() {
    assertThat(iterationOrder(ADAPTER.breadthFirstTraversal(h))).isEqualTo("hdegabcf");
  }

  public void testUsing() {

   *
   * @deprecated Use {@link com.google.common.graph.Traverser#depthFirstPostOrder} instead, which
   *     has the same behavior.
   */
  @Deprecated
  public final FluentIterable<T> postOrderTraversal(final T root) {
    checkNotNull(root);
    return new FluentIterable<T>() {
      @Override
      public UnmodifiableIterator<T> iterator() {
        return postOrderIterator(root);
      }

        return viewer.preOrderTraversal(root);
      }
    },
    POST_ORDER {
      @Override
      <T> Iterable<T> view(T root, TreeTraverser<T> viewer) {
        return viewer.postOrderTraversal(root);
      }
    },
    BREADTH_FIRST {
      @Override
      <T> Iterable<T> view(T root, TreeTraverser<T> viewer) {
        return viewer.breadthFirstTraversal(root);
      }
    };