}

        if (graph == null) {
            return null;
        }

        final MetadataGraphVertex entry = graph.getEntry();
        if (entry == null) {
            return null;
        }

        if (graph.isEmpty()) {
            throw new GraphConflictResolutionException("graph with an entry, but not vertices do not exist");

        list.addLast("1");
        list.addLast("2");
        list.addLast("3");
        assertThat(list.getEntry(0).getElement(), is("1"));
        assertThat(list.getEntry(1).getElement(), is("2"));
        assertThat(list.getEntry(2).getElement(), is("3"));
        try {
            list.getEntry(-1);
            fail();
        } catch (final ClIndexOutOfBoundsException ex) {
            System.out.println(ex);

     */
    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;

  }

  @Override
  Entry<E> getEntry(int index) {
    return Multisets.immutableEntry(elementSet.asList().get(index), getCount(index));
  }

  @Override
  @CheckForNull
  public Entry<E> firstEntry() {
    return isEmpty() ? null : getEntry(0);
  }

  @Override
  @CheckForNull
  public Entry<E> lastEntry() {
    return isEmpty() ? null : getEntry(length - 1);
  }

  @Override

    @J2ktIncompatible // serialization
    @GwtIncompatible // serialization
    Object writeReplace() {
      return super.writeReplace();
    }
  }

  @Override
  Entry<E> getEntry(int index) {
    return contents.getEntry(index);
  }

  @GwtIncompatible
  private static class SerializedForm implements Serializable {
    final Object[] elements;
    final int[] counts;

        ExtensionDescriptor extensionDescriptor = null;

        if (extensionJar.isFile()) {
            try (JarFile pluginJar = new JarFile(extensionJar, false)) {
                ZipEntry pluginDescriptorEntry = pluginJar.getEntry(getExtensionDescriptorLocation());

                if (pluginDescriptorEntry != null) {
                    try (InputStream is = pluginJar.getInputStream(pluginDescriptorEntry)) {

                // single entry in the classpath, populated from itself
                ArtifactMetadata amd = cleanGraph.getEntry().getMd();
                cpc.add(amd);
            } else {
                ClasspathGraphVisitor v = new ClasspathGraphVisitor(cleanGraph, cpc);
                MetadataGraphVertex entry = cleanGraph.getEntry();
                // entry point
                v.visit(entry);
            }

            return cpc;

    }
  }

  static <K, V> ReferenceEntry<K, V> getReferenceEntry(Cache<K, V> cache, K key) {
    checkNotNull(cache);
    checkNotNull(key);
    LocalCache<K, V> map = toLocalCache(cache);
    return map.getEntry(key);
  }

  /**
   * Forces the segment containing the given {@code key} to expand (see {@link Segment#expand()}).
   */
  static <K, V> void forceExpandSegment(Cache<K, V> cache, K key) {

      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);