* #entrySet} of {@link #descendingMap}. If you override {@code descendingMap}, you may wish to
   * override {@code lastEntry} to forward to this implementation.
   */
  protected @Nullable Entry<K, V> standardLastEntry() {
    return Iterables.<@Nullable Entry<K, V>>getFirst(descendingMap().entrySet(), null);
  }

  /**
   * A sensible definition of {@link #lastKey} in terms of {@code lastEntry}. If you override {@code

   * #entrySet} of {@link #descendingMap}. If you override {@code descendingMap}, you may wish to
   * override {@code lastEntry} to forward to this implementation.
   */
  protected @Nullable Entry<K, V> standardLastEntry() {
    return Iterables.<@Nullable Entry<K, V>>getFirst(descendingMap().entrySet(), null);
  }

  /**
   * A sensible definition of {@link #lastKey} in terms of {@code lastEntry}. If you override {@code