AsyncFunction<Foo, BarChild> function =
        new AsyncFunction<Foo, BarChild>() {
          @Override
          public AbstractFuture<BarChild> apply(Foo unused) {
            AbstractFuture<BarChild> future = new AbstractFuture<BarChild>() {};
            future.set(barChild);
            return future;
          }
        };

    AsyncFunction<Foo, BarChild> function =
        new AsyncFunction<Foo, BarChild>() {
          @Override
          public AbstractFuture<BarChild> apply(Foo unused) {
            AbstractFuture<BarChild> future = new AbstractFuture<BarChild>() {};
            future.set(barChild);
            return future;
          }
        };