@Override
  public Set<Entry<K, V>> entrySet() {
    Set<Entry<K, V>> es = entrySet;
    return (es != null) ? es : (entrySet = new EntrySet());
  }

  // Iterator Support

  abstract class HashIterator<T> implements Iterator<T> {

    int nextSegmentIndex;
    int nextTableIndex;
    @CheckForNull Segment<K, V, E, S> currentSegment;
    @CheckForNull AtomicReferenceArray<E> currentTable;