/**
     * Notify pending loads that a new value was set. This is only relevant to loading value
     * references.
     */
    void notifyNewValue(@CheckForNull V newValue);

    /**
     * Returns true if a new value is currently loading, regardless of whether there is an existing

    private @Nullable V value;
    boolean loading = false;

    public DummyValueReference() {
      this.loading = true;
    }

    public DummyValueReference(V value) {
      this.value = value;
    }

    public static <K, V> DummyValueReference<K, V> create(V value) {
      return new DummyValueReference<>(value);
    }

    private @Nullable V value;
    boolean loading = false;

    public DummyValueReference() {
      this.loading = true;
    }

    public DummyValueReference(V value) {
      this.value = value;
    }

    public static <K, V> DummyValueReference<K, V> create(V value) {
      return new DummyValueReference<>(value);
    }

    class Holder {

      int value = 2;
    }
    final Holder holder = new Holder();

    // This function adds the holder's value to the input value.
    Function<Integer, Integer> adder =
        new Function<Integer, Integer>() {
          @Override
          public Integer apply(Integer from) {
            return from + holder.value;
          }
        };

    class Holder {

      int value = 2;
    }
    final Holder holder = new Holder();

    // This function adds the holder's value to the input value.
    Function<Integer, Integer> adder =
        new Function<Integer, Integer>() {
          @Override
          public Integer apply(Integer from) {
            return from + holder.value;
          }
        };

    /**
     * Notify pending loads that a new value was set. This is only relevant to loading value
     * references.
     */
    void notifyNewValue(@CheckForNull V newValue);

    /**
     * Returns true if a new value is currently loading, regardless of whether there is an existing

  }

  /**
   * A transformation of the value of a key-value pair, using both key and value as inputs. To apply
   * the transformation to a map, use {@link Maps#transformEntries(Map, EntryTransformer)}.
   *
   * @param <K> the key type of the input and output entries
   * @param <V1> the value type of the input entry
   * @param <V2> the value type of the output entry
   * @since 7.0
   */

 * asynchronously-computed intermediate value, or else an exception that indicates the failure or
 * cancellation of the operation so far. The only way to extract the value or exception from a step
 * is by declaring that step to be the last step of the pipeline. Nevertheless, we refer to the
 * "value" of a successful step or the "result" (value or exception) of any step.
 *
 * <ol>