*
   * <p>If you override {@link #entrySet()}, you may wish to override {@link #pollFirstEntry()} to
   * forward to this implementation.
   */
  @CheckForNull
  protected Entry<E> standardPollFirstEntry() {
    Iterator<Entry<E>> entryIterator = entrySet().iterator();
    if (!entryIterator.hasNext()) {
      return null;
    }
    Entry<E> entry = entryIterator.next();

   * entrySet}. If you override {@code entrySet}, you may wish to override {@code pollFirstEntry} to
   * forward to this implementation.
   */
  @CheckForNull
  protected Entry<K, V> standardPollFirstEntry() {
    return Iterators.pollNext(entrySet().iterator());
  }

  @Override
  @CheckForNull
  public Entry<K, V> pollLastEntry() {
    return delegate().pollLastEntry();
  }

  /**

   * entrySet}. If you override {@code entrySet}, you may wish to override {@code pollFirstEntry} to
   * forward to this implementation.
   */
  @CheckForNull
  protected Entry<K, V> standardPollFirstEntry() {
    return Iterators.pollNext(entrySet().iterator());
  }

  @Override
  @CheckForNull
  public Entry<K, V> pollLastEntry() {
    return delegate().pollLastEntry();
  }

  /**