@GwtCompatible
public enum ListFeature implements Feature<List> {
  SUPPORTS_SET,
  SUPPORTS_ADD_WITH_INDEX(CollectionFeature.SUPPORTS_ADD),
  SUPPORTS_REMOVE_WITH_INDEX(CollectionFeature.SUPPORTS_REMOVE),

  GENERAL_PURPOSE(
      CollectionFeature.GENERAL_PURPOSE,
      SUPPORTS_SET,
      SUPPORTS_ADD_WITH_INDEX,
      SUPPORTS_REMOVE_WITH_INDEX),

  /** Features supported by lists where only removal is allowed. */

    @Override
    public void add(int index, E element) {
      synchronized (mutex) {
        delegate().add(index, element);
      }
    }

    @Override
    public boolean addAll(int index, Collection<? extends E> c) {
      synchronized (mutex) {
        return delegate().addAll(index, c);
      }
    }

    @Override
    public E get(int index) {
      synchronized (mutex) {

  }

  private void doTestSet(E newValue) {
    int index = aValidIndex();
    E initialValue = getList().get(index);
    assertEquals(
        "set(i, x) should return the old element at position i.",
        initialValue,
        getList().set(index, newValue));
    assertEquals("After set(i, x), get(i) should return x", newValue, getList().get(index));

    abstract E get(int index);

    @Override
    public UnmodifiableIterator<E> iterator() {
      return asList().iterator();
    }

    @Override
    ImmutableList<E> createAsList() {
      return new ImmutableAsList<E>() {
        @Override
        public E get(int index) {
          return Indexed.this.get(index);
        }

        @Override

          return i - start;
        }
      }
      return -1;
    }

    @Override
    public Float set(int index, Float element) {
      checkElementIndex(index, size());
      float oldValue = array[start + index];
      // checkNotNull for GWT (do not optimize)
      array[start + index] = checkNotNull(element);
      return oldValue;
    }

    @Override

  }

  @Override
  public ImmutableList<E> get(int index) {
    checkElementIndex(index, size());
    return new ImmutableList<E>() {

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

      @Override
      public E get(int axis) {
        checkElementIndex(axis, size());
        int axisIndex = getAxisIndexForProductIndex(index, axis);
        return axes.get(axis).get(axisIndex);

      int mask = hashTable.length - 1;
      for (int i = i0; i - i0 < maxRunBeforeFallback; i++) {
        int index = i & mask;
        Object tableEntry = hashTable[index];
        if (tableEntry == null) {
          addDedupedElement(e);
          hashTable[index] = e;
          hashCode += eHash;
          ensureTableCapacity(distinct); // rebuilds table if necessary
          return this;

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

  @Override
  int indexOf(@CheckForNull Object target) {
    int index = forward.indexOf(target);
    if (index == -1) {
      return index;
    } else {
      return size() - 1 - index;
    }
  }

  @Override
  boolean isPartialView() {
    return forward.isPartialView();
  }

    size = 0;
    distinctElements = 0;
  }

  abstract class Itr<T> implements Iterator<T> {
    int index = 0;
    int toRemove = -1;

    abstract T output(int index);

    @Override
    public boolean hasNext() {
      for (; index < enumConstants.length; index++) {
        if (counts[index] > 0) {
          return true;
        }
      }
      return false;
    }

    @Override

    ImmutableListMultimap<Integer, String> index =
        FluentIterable.from(asList("one", "two", "three", "four"))
            .index(
                new Function<String, Integer>() {
                  @Override
                  public Integer apply(String input) {
                    return input.length();
                  }
                });
    assertEquals(expected, index);
  }