public void PhotosGetContactsPhotosAsyncTest()
        {
            var w = new AsyncSubject <FlickrResult <PhotoCollection> >();

            AuthInstance.PhotosGetContactsPhotosAsync(50, true, true, true, PhotoSearchExtras.All, r => { w.OnNext(r); w.OnCompleted(); });
            var result = w.Next().First();

            Assert.IsFalse(result.HasError);
            Assert.IsNotNull(result.Result);

            Assert.IsTrue(result.Result.Count > 0, "Should return some photos.");
        }