@Override
  @CheckForNull
  public E lower(E element) {
    return forward.higher(element);
  }

  @Override
  @CheckForNull
  public E floor(E element) {
    return forward.ceiling(element);
  }

  @Override
  @CheckForNull
  public E ceiling(E element) {
    return forward.floor(element);
  }

  @Override
  @CheckForNull
  public E higher(E element) {
    return forward.lower(element);
  }

        title.appendChild(literal);
        literal.appendChild(document.createTextNode(blockDoc.getName()));
        title.appendChild(document.createTextNode(" { }"));

        warningsRenderer.renderTo(blockDoc, "script block", section);

        for (Element element : blockDoc.getComment()) {
            section.appendChild(document.importNode(element, true));
        }

  }

  protected void expectMissingKeys(K... elements) {
    for (K element : elements) {
      assertFalse("Should not contain key " + element, getMap().containsKey(element));
    }
  }

  protected void expectMissingValues(V... elements) {
    for (V element : elements) {
      assertFalse("Should not contain value " + element, getMap().containsValue(element));
    }
  }

  @Override
  public int add(@ParametricNullness E element, int occurrences) {
    checkNonnegative(occurrences, "occurrences");
    if (occurrences == 0) {
      return count(element);
    }
    checkArgument(range.contains(element));
    AvlNode<E> root = rootReference.get();
    if (root == null) {
      int unused = comparator().compare(element, element);
      AvlNode<E> newRoot = new AvlNode<>(element, occurrences);

            Element element = document.createElement("NO-VALUE-FOR_FIELD");
            element.appendChild(document.createTextNode(targetClass.getClassName() + ":" + parts[1]));
            return element;
        }

        return createLiteralNode(value);
    }

    private Node createLiteralNode(String value) {
        Element element = document.createElement("literal");

  final transient E element;

  SingletonImmutableSet(E element) {
    this.element = Preconditions.checkNotNull(element);
  }

  @Override
  public int size() {
    return 1;
  }

  @Override
  public boolean contains(@CheckForNull Object target) {
    return element.equals(target);
  }

  @Override
  public UnmodifiableIterator<E> iterator() {

 */
public class Indexed<T> {

    /** 要素 */
    private final T element;

    /** 要素のインデックス */
    private final int index;

    /**
     * コンストラクタ
     *
     * @param element
     *            要素
     * @param index
     *            要素のインデックス
     */
    public Indexed(final T element, final int index) {
        this.element = element;
        this.index = index;
    }

    /**
     * 要素を返します。

    public abstract Builder<E> add(E element);

    @CanIgnoreReturnValue
    public Builder<E> add(E... elements) {
      checkNotNull(elements); // for GWT
      for (E element : elements) {
        add(checkNotNull(element));
      }
      return this;
    }

    @CanIgnoreReturnValue
    public Builder<E> addAll(Iterable<? extends E> elements) {
      checkNotNull(elements); // for GWT

             */
            requireNonNull(element);
            if (visited.add(element)) {
              return element;
            }
          }
          horizon.removeFirst();
          return null;
        }
      };
    }

    int[] entries = requireEntries();
    @Nullable Object[] elements = requireElements();
    int srcIndex = size() - 1;
    if (dstIndex < srcIndex) {
      // move last entry to deleted spot
      Object object = elements[srcIndex];
      elements[dstIndex] = object;
      elements[srcIndex] = null;

      // move the last entry to the removed spot, just like we moved the element
      entries[dstIndex] = entries[srcIndex];