*/
    @DoNotCall
    @Deprecated
    @Override
    public final ImmutableSortedMap<K, V> buildKeepingLast() {
      // TODO(emcmanus): implement
      throw new UnsupportedOperationException(
          "ImmutableSortedMap.Builder does not yet implement buildKeepingLast()");
    }
  }

  private final transient RegularImmutableSortedSet<K> keySet;
  private final transient ImmutableList<V> valueList;

   * generated by {@code factory}.
   *
   * <p><b>Warning: do not use</b> this method when the collections returned by {@code factory}
   * implement either {@link List} or {@code Set}! Use the more specific method {@link
   * #newListMultimap}, {@link #newSetMultimap} or {@link #newSortedSetMultimap} instead, to avoid
   * very surprising behavior from {@link Multimap#equals}.