// TODO(fry): rename get, then extend AbstractFuture instead of containing SettableFuture
    final SettableFuture<V> futureValue = SettableFuture.create();
    final Stopwatch stopwatch = Stopwatch.createUnstarted();

    public LoadingValueReference() {
      this(null);
    }

    public LoadingValueReference(@CheckForNull ValueReference<K, V> oldValue) {