@Override
        protected Entry<K, V> get(final int index) {
          return getEntry(index);
        }
      };
    }

    // TODO(lowasser): consider an optimized values() implementation

    @Override
    public boolean containsKey(@CheckForNull Object key) {
      return keyIndex.containsKey(key);
    }

    @CheckForNull
    @Override

    }

    @Override
    Spliterator<Entry<K, V>> entrySpliterator() {
      return CollectSpliterators.indexed(size(), Spliterator.ORDERED, this::getEntry);
    }

    // TODO(lowasser): consider an optimized values() implementation

    @Override
    public boolean containsKey(@CheckForNull Object key) {
      return keyIndex.containsKey(key);
    }

    @CheckForNull
    @Override