return entry.getValue();
      }
    };
  }

  static <K extends @Nullable Object, V extends @Nullable Object>
      UnmodifiableIterator<Entry<K, V>> unmodifiableEntryIterator(
          final Iterator<Entry<K, V>> entryIterator) {
    return new UnmodifiableIterator<Entry<K, V>>() {
      @Override
      public boolean hasNext() {
        return entryIterator.hasNext();
      }

      @Override