Перегрузка WebClient.GetRequest() и передача исключения вверх по стеку

//CookieAwareWebClient.cs
using System;
using System.Net;
using TextAlias = System.Text;
public class CookieAwareWebClient : WebClient
{
    public CookieAwareWebClient(CookieContainer requestCookieContainer = null, string method = WebRequestMethods.Http.Get, bool allowAutoRedirect = false, int timeout = 30000, CookieReplacementType cookieReplacementType = CookieReplacementType.None, string contentType = null, string postString = null, string referer = null, string userAgent = "Opera/9.80 (Windows NT 6.1; U; ru) Presto/2.10.229 Version/11.61")
    {
        RequestCookieContainer = requestCookieContainer;
        Method = method;
        AllowAutoRedirect = allowAutoRedirect;
        Timeout = timeout;
        CookieReplacementType = cookieReplacementType;
        ContentType = contentType;
        PostString = postString;
        Referer = referer;
        UserAgent = userAgent;
    }
 
    public bool AllowAutoRedirect { get; set; }
    public CookieReplacementType CookieReplacementType { get; set; }
    public CookieContainer RequestCookieContainer { get; set; }
    public CookieCollection ResponseCookieCollection { get; private set; }
    public string ContentType { get; set; }
    public HttpWebRequest LastRequest { get; private set; }
    public HttpWebResponse LastResponse { get; private set; }
    public string Method { get; set; }
    public string PostString { get; set; }
    public string Referer { get; set; }
    public int Timeout { get; set; }
    public string UserAgent { get; set; }
 
    public void GetServerResponse(string address)
    {
        var request = GetWebRequest(new Uri(address));
        var response = GetWebResponse(request);
    }
    protected override WebRequest GetWebRequest(Uri address)
    {
        var request = base.GetWebRequest(address) as HttpWebRequest;
        LastRequest = request;
        if (request != null)
        {
            request.CookieContainer = RequestCookieContainer;
            request.Method = Method;
            request.AllowAutoRedirect = AllowAutoRedirect;
            request.ContentType = ContentType;
            request.Referer = Referer;
            request.Timeout = Timeout;
            request.UserAgent = UserAgent;
        }
        request.AutomaticDecompression = DecompressionMethods.GZip | DecompressionMethods.Deflate;
        return request;
    }
 
    protected override WebResponse GetWebResponse(WebRequest request)
    {
        if (Method == WebRequestMethods.Http.Post)
        {
            SendPOST(request, PostString);
        }
        var response = base.GetWebResponse(request) as HttpWebResponse;
        LastResponse = response;
        if (response != null)
        {
            ResponseCookieCollection = response.Cookies;
            switch (CookieReplacementType)
            {
                case CookieReplacementType.Add:
                    RequestCookieContainer.Add(ResponseCookieCollection);
                    break;
                case CookieReplacementType.Replace:
                    RequestCookieContainer = new CookieContainer();
                    RequestCookieContainer.Add(ResponseCookieCollection);
                    break;
                case CookieReplacementType.None:
                    break;
                default:
                    throw new ArgumentException("Nonsupported value.");
            }
        }
        return response;
    }
 
 
    protected virtual void SendPOST(WebRequest request, string postString = null)
    {
        if (postString != null && postString.Length > 0)
        {
            var encoding = TextAlias.Encoding.ASCII;
            var postBytes = encoding.GetBytes(postString);
 
            SendPOST(request, postBytes);
        }
    }
 
    protected virtual void SendPOST(WebRequest request, byte[] postBytes)
    {
        if (postBytes.Length > 0)
        {
            request.ContentLength = postBytes.Length;
 
            using (var newStream = request.GetRequestStream())
            {
                newStream.Write(postBytes, 0, postBytes.Length);
            }
        }
    }
}
 
public enum CookieReplacementType
{
    None, Add, Replace
}

//Program.cs
using System;
using System.Net;
 
namespace WindowsApplication1
{
    class Program
    {
        static void Main()
        {
            Console.WriteLine("Started.");
            try
            {
                Download();
                Console.WriteLine("Downloaded.");
            }
            catch (WebException e)
            {
                Console.WriteLine("Occurred: {0}.", e.Message);
            }
            finally
            {
                Console.WriteLine("Finished.");
            }
            Console.ReadLine();
        }
 
        public static string Download()
        {
            Console.WriteLine("Start: A.Download()");
            string html;
            using (var wc = new CookieAwareWebClient())
            {
                html = wc.DownloadString("http://microsoft.com/");
            }
            Console.WriteLine("End: A.Download()");
            return html;
        }
    }
}