The Gryphon lifted up both its paws in surprise.  `What!  Never
heard of uglifying!' it exclaimed.  `You know what to beautify is,
I suppose?'

  `Yes,' said Alice doubtfully:  `it means--to--make--anything--prettier.'

  `Well, then,' the Gryphon went on, `if you don't know what to
uglify is, you ARE a simpleton.'

  Alice did not feel encouraged to ask any more questions about

  The Gryphon lifted up both its paws in surprise.  `What!  Never
heard of uglifying!' it exclaimed.  `You know what to beautify is,
I suppose?'

  `Yes,' said Alice doubtfully:  `it means--to--make--anything--prettier.'

  `Well, then,' the Gryphon went on, `if you don't know what to
uglify is, you ARE a simpleton.'

  Alice did not feel encouraged to ask any more questions about

   * }</pre>
   *
   * <p>If your index may associate multiple values with each key, use {@link
   * Multimaps#index(Iterable, Function) Multimaps.index}.
   *
   * <p><b>Note:</b> on Java 8+, it is usually better to use streams. For example:
   *
   * <pre>{@code
   * import static com.google.common.collect.ImmutableMap.toImmutableMap;
   * ...
   * ImmutableMap<String, Color> colorForName =

              return function.toString();
            }
          },
          executor);
    }
  }

  @Override
  public String toString() {
    // TODO(dpb): Better toString, in the style of Futures.transform etc.
    return toStringHelper(this).add("state", state.get()).addValue(future).toString();
  }

  @SuppressWarnings("removal") // b/260137033
  @Override