*
   * @param iterable the iterable to copy
   * @return a newly-allocated array into which all the elements of the iterable have been copied
   */
  static @Nullable Object[] toArray(Iterable<?> iterable) {
    return castOrCopyToCollection(iterable).toArray();
  }

  /**
   * Converts an iterable into a collection. If the iterable is already a collection, it is

    }
  }

  private void testGetOnAbc(Iterable<String> iterable) {
    try {
      Iterables.get(iterable, -1);
      fail();
    } catch (IndexOutOfBoundsException expected) {
    }
    assertEquals("a", Iterables.get(iterable, 0));
    assertEquals("b", Iterables.get(iterable, 1));
    assertEquals("c", Iterables.get(iterable, 2));
    try {
      Iterables.get(iterable, 3);
      fail();

    }
  }

  private void testGetOnAbc(Iterable<String> iterable) {
    try {
      Iterables.get(iterable, -1);
      fail();
    } catch (IndexOutOfBoundsException expected) {
    }
    assertEquals("a", Iterables.get(iterable, 0));
    assertEquals("b", Iterables.get(iterable, 1));
    assertEquals("c", Iterables.get(iterable, 2));
    try {
      Iterables.get(iterable, 3);
      fail();

     *
     * @param <E>
     *            要素の型
     * @param iterables
     *            {@link Iterable}の並び。{@literal null}であってはいけません
     * @return {@link MultiIterator}をラップした{@link Iterable}
     */
    public static <E> Iterable<E> iterable(final Iterable<E>... iterables) {
        assertArgumentNotNull("iterables", iterables);

        @SuppressWarnings("unchecked")

   * they are returned by the iterable's iterator.
   *
   * @since 12.0
   */
  public static <E> ArrayDeque<E> newArrayDeque(Iterable<? extends E> elements) {
    if (elements instanceof Collection) {
      return new ArrayDeque<>((Collection<? extends E>) elements);
    }
    ArrayDeque<E> deque = new ArrayDeque<>();
    Iterables.addAll(deque, elements);
    return deque;

  // Ordering<Iterable<String>> o =
  //     Ordering.<String>natural().lexicographical();
  public <S extends T> Ordering<Iterable<S>> lexicographical() {
    /*
     * Note that technically the returned ordering should be capable of
     * handling not just {@code Iterable<S>} instances, but also any {@code
     * Iterable<? extends S>}. However, the need for this comes up so rarely

     *
     * @param clazz
     *            クラス。{@literal null}であってはいけません
     * @return {@link ClassIterator}をラップした{@link Iterable}
     */
    public static Iterable<Class<?>> iterable(final Class<?> clazz) {
        return iterable(clazz, true);
    }

    /**
     * for each構文で使用するために{@link ClassIterator}をラップした{@link Iterable}を返します。
     *
     * @param clazz

     *
     * @param <T>
     *            {@link Iterable}の要素型
     * @param iterable
     *            {@link Iterable}。{@literal null}であってはいけません
     * @return {@link IndexedIterator}をラップした{@link Iterable}
     */
    public static <T> Iterable<Indexed<T>> indexed(final Iterable<T> iterable) {
        assertArgumentNotNull("iterable", iterable);

   *     original iterable.
   * @throws NullPointerException if the specified iterable is null or has any null elements.
   * @since 12.0
   */
  public static <E extends Comparable<? super E>> Collection<List<E>> orderedPermutations(
      Iterable<E> elements) {
    return orderedPermutations(elements, Ordering.natural());
  }

  /**
   * Returns a {@link Collection} of all the permutations of the specified {@link Iterable} using

    /**
     * for each構文で使用するために{@link LineIterator}をラップした{@link Iterable}を返します。
     *
     * @param reader
     *            文字列を読み込む{@link Reader}。{@literal null}であってはいけません
     * @return {@link LineIterator}をラップした{@link Iterable}
     */
    public static Iterable<String> iterable(final Reader reader) {
        assertArgumentNotNull("reader", reader);
        return iterable(new BufferedReader(reader));
    }

    /**