new TreeTraverser<Tree>() {
        @Override
        public Iterable<Tree> children(Tree node) {
          return node.children;
        }
      };

  private static final TreeTraverser<Tree> ADAPTER_USING_USING =
      TreeTraverser.using(
          new Function<Tree, Iterable<Tree>>() {
            @Override
            public Iterable<Tree> apply(Tree node) {
              return node.children;
            }

     *
     * @return {@link PropertyDesc}の数
     */
    int getPropertyDescSize();

    /**
     * {@link PropertyDesc}の{@link Iterable}を返します。
     *
     * @return {@link PropertyDesc}の{@link Iterable}
     */
    Iterable<PropertyDesc> getPropertyDescs();

    /**
     * {@link FieldDesc}を持っているかどうかを返します。
     *
     * @param fieldName

    }

    /**
     * {@link IteratorEnumeration}を作成します。
     *
     * @param iterable
     *            反復可能なオブジェクト。{@literal null}であってはいけません
     */
    public IteratorEnumeration(final Iterable<T> iterable) {
        assertArgumentNotNull("iterable", iterable);
        this.iterator = iterable.iterator();
    }

    @Override
    public boolean hasMoreElements() {
        return iterator.hasNext();

  protected ListIteratorTester(
      int steps,
      Iterable<E> elementsToInsert,
      Iterable<? extends IteratorFeature> features,
      Iterable<E> expectedElements,
      int startIndex) {
    super(steps, elementsToInsert, features, expectedElements, KnownOrder.KNOWN_ORDER, startIndex);
  }

  @Override
  protected final Iterable<? extends Stimulus<E, ? super ListIterator<E>>> getStimulusValues() {

  protected ListIteratorTester(
      int steps,
      Iterable<E> elementsToInsert,
      Iterable<? extends IteratorFeature> features,
      Iterable<E> expectedElements,
      int startIndex) {
    super(steps, elementsToInsert, features, expectedElements, KnownOrder.KNOWN_ORDER, startIndex);
  }

  @Override
  protected final Iterable<? extends Stimulus<E, ? super ListIterator<E>>> getStimulusValues() {

    /**
     * for each構文で使用するために{@link SingleValueIterator}をラップした{@link Iterable}を返します。
     *
     * @param <E>
     *            要素の型
     * @param value
     *            反復子が返す唯一の値
     * @return {@link SingleValueIterator}をラップした{@link Iterable}
     */
    public static <E> Iterable<E> iterable(final E value) {
        return () -> new SingleValueIterator<>(value);
    }

    /**

    TypeToken<ImmutableList<Integer>[]> type = new TypeToken<ImmutableList<Integer>[]>() {};
    ImmutableTypeToInstanceMap<Iterable<?>[]> map =
        ImmutableTypeToInstanceMap.<Iterable<?>[]>builder().put(type, array).build();
    assertEquals(1, map.size());
    // Redundant cast works around a javac bug.
    assertThat((Iterable<?>[]) map.getInstance(type)).asList().containsExactly(array[0]);
  }

  public void testWildcardType() {

  }

  public void testDoubler() {
    Iterable<Integer> doubled =
        new Iterable<Integer>() {
          @Override
          public Iterator<Integer> iterator() {
            return newDoubler(2, 32);
          }
        };
    assertThat(doubled).containsExactly(2, 4, 8, 16, 32).inOrder();
  }

  public void testSampleCode() {
    Iterable<Integer> actual =
        new Iterable<Integer>() {
          @Override

    private final boolean errors;

    private final T value;

    private final Iterable<? extends ModelProblem> problems;

    private Result(boolean errors, T model, Iterable<? extends ModelProblem> problems) {
        this.errors = errors;
        this.value = model;
        this.problems = problems;
    }

    public Iterable<? extends ModelProblem> getProblems() {
        return problems;
    }

      default:
        return create(elements);
    }
  }

  public static <E> ImmutableSet<E> copyOf(Collection<? extends E> elements) {
    Iterable<? extends E> iterable = elements;
    return copyOf(iterable);
  }

  public static <E> ImmutableSet<E> copyOf(Iterable<? extends E> elements) {
    if (elements instanceof ImmutableSet && !(elements instanceof ImmutableSortedSet)) {