}

  /**
   * Creates a fresh entry with the specified object at the specified position in the entry arrays.
   */
  void insertEntry(int entryIndex, @ParametricNullness E object, int hash, int mask) {
    setEntry(entryIndex, CompactHashing.maskCombine(hash, UNSET, mask));
    setElement(entryIndex, object);
  }

  /** Resizes the entries storage if necessary. */
  private void resizeMeMaybe(int newSize) {

        }

        return count;
    }

    // ------------------------------------------------------------------------
    public MetadataGraphVertex getEntry() {
        return entry;
    }

    public void setEntry(MetadataGraphVertex entry) {
        this.entry = entry;
    }

    public TreeSet<MetadataGraphVertex> getVertices() {
        return vertices;
    }

  }

  /**
   * Creates a fresh entry with the specified object at the specified position in the entry arrays.
   */
  void insertEntry(int entryIndex, @ParametricNullness E object, int hash, int mask) {
    setEntry(entryIndex, CompactHashing.maskCombine(hash, UNSET, mask));
    setElement(entryIndex, object);
  }

  /** Resizes the entries storage if necessary. */
  private void resizeMeMaybe(int newSize) {

      return range.upperBound;
    }
  }

  @Override
  @CheckForNull
  public V get(K key) {
    Entry<Range<K>, V> entry = getEntry(key);
    return (entry == null) ? null : entry.getValue();
  }

  @Override
  @CheckForNull
  public Entry<Range<K>, V> getEntry(K key) {
    Entry<Cut<K>, RangeMapEntry<K, V>> mapEntry =
        entriesByLowerBound.floorEntry(Cut.belowValue(key));

     */
    public E get(final int index) {
        return getEntry(index).element;
    }

    /**
     * インデックスで指定された位置に要素を設定します。
     *
     * @param index
     *            インデックス
     * @param element
     *            要素
     * @return 元の要素
     */
    public E set(final int index, final E element) {
        final Entry entry = getEntry(index);
        final E oldValue = entry.element;

      return range.upperBound;
    }
  }

  @Override
  @CheckForNull
  public V get(K key) {
    Entry<Range<K>, V> entry = getEntry(key);
    return (entry == null) ? null : entry.getValue();
  }

  @Override
  @CheckForNull
  public Entry<Range<K>, V> getEntry(K key) {
    Entry<Cut<K>, RangeMapEntry<K, V>> mapEntry =
        entriesByLowerBound.floorEntry(Cut.belowValue(key));

    assertEquals(1, segment.count);
    assertSame(newValue, segment.get(key, hash));

    // cleared
    InternalEntry<Object, Object, ?> entry = segment.getEntry(key, hash);
    WeakValueReference<Object, Object, ?> oldValueRef =
        segment.newWeakValueReferenceForTesting(entry, oldValue);
    segment.setWeakValueReferenceForTesting(entry, oldValueRef);

    assertEquals(1, segment.count);
    assertSame(newValue, segment.get(key, hash));

    // cleared
    InternalEntry<Object, Object, ?> entry = segment.getEntry(key, hash);
    WeakValueReference<Object, Object, ?> oldValueRef =
        segment.newWeakValueReferenceForTesting(entry, oldValue);
    segment.setWeakValueReferenceForTesting(entry, oldValueRef);

    checkElementIndex(index, size);
    return values[index];
  }

  void setValue(int index, int newValue) {
    checkElementIndex(index, size);
    values[index] = newValue;
  }

  Entry<K> getEntry(int index) {
    checkElementIndex(index, size);
    return new MapEntry(index);
  }

  class MapEntry extends AbstractEntry<K> {
    @ParametricNullness final K key;

    int lastKnownIndex;

    @Override
    public int size() {
      return keyIndex.size();
    }

    @Override
    public boolean isEmpty() {
      return keyIndex.isEmpty();
    }

    Entry<K, V> getEntry(final int index) {
      checkElementIndex(index, size());
      return new AbstractMapEntry<K, V>() {
        @Override
        public K getKey() {
          return ArrayMap.this.getKey(index);
        }