SoapExtension eksempel fra MSDN

Har prøvet eksemplet fra Microsoft for at logge soap, men det ser ikke ud som om den i det hele taget kommer ind i koden. Er det mig der gør noget forkert?
Fra http://msdn2.microsoft.com/en-us/library/system.web.services.protocols.soapextension(VS.80).aspx
using System;
using System.Web.Services;
using System.Web.Services.Protocols;
using System.IO;
using System.Net;

// Define a SOAP Extension that traces the SOAP request and SOAP
// response for the XML Web service method the SOAP extension is
// applied to.

public class TraceExtension : SoapExtension
{
  Stream oldStream;
  Stream newStream;
  string filename;

  // Save the Stream representing the SOAP request or SOAP response into
  // a local memory buffer.
  public override Stream ChainStream(Stream stream)
  {
    oldStream = stream;
    newStream = new MemoryStream();
    return newStream;
  }

  // When the SOAP extension is accessed for the first time, the XML Web
  // service method it is applied to is accessed to store the file
  // name passed in, using the corresponding SoapExtensionAttribute.   
  public override object GetInitializer(LogicalMethodInfo methodInfo, SoapExtensionAttribute attribute)
  {
    return ((TraceExtensionAttribute)attribute).Filename;
  }

  // The SOAP extension was configured to run using a configuration file
  // instead of an attribute applied to a specific XML Web service
  // method.
  public override object GetInitializer(Type WebServiceType)
  {
    // Return a file name to log the trace information to, based on the
    // type.
    return "C:\\" + WebServiceType.FullName + ".log";
  }

  // Receive the file name stored by GetInitializer and store it in a
  // member variable for this specific instance.
  public override void Initialize(object initializer)
  {
    filename = (string)initializer;
  }

  //  If the SoapMessageStage is such that the SoapRequest or
  //  SoapResponse is still in the SOAP format to be sent or received,
  //  save it out to a file.
  public override void ProcessMessage(SoapMessage message)
  {
    switch (message.Stage)
    {
      case SoapMessageStage.BeforeSerialize:
        break;
      case SoapMessageStage.AfterSerialize:
        WriteOutput(message);
        break;
      case SoapMessageStage.BeforeDeserialize:
        WriteInput(message);
        break;
      case SoapMessageStage.AfterDeserialize:
        break;
      default:
        throw new Exception("invalid stage");
    }
  }

  public void WriteOutput(SoapMessage message)
  {
    newStream.Position = 0;
    FileStream fs = new FileStream(filename, FileMode.OpenOrCreate,
        FileAccess.Write);
    StreamWriter w = new StreamWriter(fs);

    string soapString = (message is SoapServerMessage) ? "SoapResponse" : "SoapRequest";
    w.WriteLine("-----" + soapString + " at " + DateTime.Now);
    w.Flush();
    Copy(newStream, fs);
    w.Close();
    newStream.Position = 0;
    Copy(newStream, oldStream);
  }

  public void WriteInput(SoapMessage message)
  {
    Copy(oldStream, newStream);
    FileStream fs = new FileStream(filename, FileMode.OpenOrCreate,
        FileAccess.Write);
    StreamWriter w = new StreamWriter(fs);

    string soapString = (message is SoapServerMessage) ?
        "SoapRequest" : "SoapResponse";
    w.WriteLine("-----" + soapString +
        " at " + DateTime.Now);
    w.Flush();
    newStream.Position = 0;
    Copy(newStream, fs);
    w.Close();
    newStream.Position = 0;
  }

  void Copy(Stream from, Stream to)
  {
    TextReader reader = new StreamReader(from);
    TextWriter writer = new StreamWriter(to);
    writer.WriteLine(reader.ReadToEnd());
    writer.Flush();
  }
}

// Create a SoapExtensionAttribute for the SOAP Extension that can be
// applied to an XML Web service method.
[AttributeUsage(AttributeTargets.Method)]
public class TraceExtensionAttribute : SoapExtensionAttribute
{

  private string filename = "c:\\Share\\log.txt";
  private int priority;

  public override Type ExtensionType
  {
    get { return typeof(TraceExtension); }
  }

  public override int Priority
  {
    get { return priority; }
    set { priority = value; }
  }

  public string Filename
  {
    get
    {
      return filename;
    }
    set
    {
      filename = value;
    }
  }
}

Min webservice:
  [WebMethod]
  [TraceExtensionAttribute(Filename="c:log.log",Priority=0)]
  public string HelloWorld()
  {
    return "Hello World";
  }

Anyone??