Testing async methods

Hi,

I'm having difficulty in how to approach testing the following code:

        [WebMethod]
        public IAsyncResult BeginDoingStuff(ComplexObjectRequest request, AsyncCallback callback, object state)
        {
            ComplexObjectResponse response = new ComplexObjectResponse();
            AsyncResult<ComplexObjectResponse> asyncResult = new AsyncResult<ComplexObjectResponse>(callback, state);

            try
            {
                MyWorkerClass wc = new MyWorkerClass();
                wc.LongRunningOperation(asyncResult);

                return asyncResult;
            }
            catch (Exception)
            {
                response.Error = "Error!";
                asyncResult.SetAsCompleted(response, true);
                return asyncResult;
            }
        }

        [WebMethod]
        public ComplexObjectResponse EndDoingStuff(IAsyncResult call)
        {
            try
            {
                AsyncResult<ComplexObjectResponse> asyncResult = (AsyncResult<ComplexObjectResponse>)call;
                ComplexObjectResponse result = asyncResult.EndInvoke();
                return result;
            }
            catch (Exception)
            {
                ComplexObjectResponse result = new ComplexObjectResponse();
                result.Error = "Error!";
                return result;
            }

        }

Within BeginDoingStuff, a call to LongRunningOperation takes place which in this case just performs a Thread.Sleep operation for 10 seconds.

Now, my incomplete test currently looks like:

        [TestMethod(), Isolated]
        public void BeginDoingStuffTest()
        {
            WebServiceUnderTest target = new WebServiceUnderTest(); 
            ComplexObjectRequest request = new ComplexObjectRequest();

            AsyncCallback callback = null;
            IAsyncResult expected = null;
            IAsyncResult actual = null;
            object state = null;
            
            actual = target.BeginDoingStuff(request, callback, state);

            Assert.AreEqual(expected, actual);
            Assert.Inconclusive("Verify the correctness of this test method.");
        }

Out of curiosity, I ran the test in order to observe the behavior and it appeared to work correctly; It returns an IAsyncResult object (after 10 seconds) ready to be processed by the EndDoingStuff method.

My question: How can I get the unit test to execute both the Begin and End methods, taking into account the long running process in between?

I suppose the end method could be called after the Begin method has finished processing (in the test), but not sure this is the ideal approach, so I'm open to ideas and suggestions.

Note: I've tried various approaches including some blog posts on Typemock's site i.e. Here and Here, but not been able to achieve the results I want.