/// <summary>
/// Programatically registers a <see cref="SoapExtension"/> at runtime with the specified
/// <see cref="SoapExtensionTypeElement.Priority"/> and <see cref="SoapExtensionTypeElement.Group"/> settings.
/// </summary>
/// <param name="type">The <see cref="Type"/> of the <see cref="SoapExtension"/> to register.</param>
/// <param name="priority">
/// A value that indicates the relative order in which this SOAP extension runs when multiple SOAP extensions are
/// specified. Within each group the priority attribute distinguishes the overall relative priority of the SOAP
/// extension. A lower priority number indicates a higher priority for the SOAP extension. The lowest possible
/// value for the priority attribute is 1.
/// </param>
/// <param name="group">
/// The relative priority group (e.g. Low or High) in which this SOAP extension runs when multiple SOAP extensions
/// are configured to run.
/// </param>
[ReflectionPermission(SecurityAction.Demand, Unrestricted = true)]
public static void RegisterSoapExtension(Type type, int priority, PriorityGroup group)
{
   if (!type.IsSubclassOf(typeof(SoapExtension)))
   {
      throw new ArgumentException("Type must be derived from SoapException.", "type");
   }

   if (priority < 1)
   {
      throw new ArgumentOutOfRangeException("priority", priority, "Priority must be greater or equal to 1.");
   }

   // get the current web services settings...
   WebServicesSection wss = WebServicesSection.Current;

   // set SoapExtensionTypes collection to read/write...
   FieldInfo readOnlyField = typeof(System.Configuration.ConfigurationElementCollection).GetField("bReadOnly", BindingFlags.NonPublic | BindingFlags.Instance);
   readOnlyField.SetValue(wss.SoapExtensionTypes, false);

   // inject SoapExtension...
   wss.SoapExtensionTypes.Add(new SoapExtensionTypeElement(type, priority, group));

   // set SoapExtensionTypes collection back to readonly and clear modified flags...
   MethodInfo resetModifiedMethod = typeof(System.Configuration.ConfigurationElement).GetMethod("ResetModified", BindingFlags.NonPublic | BindingFlags.Instance);
   resetModifiedMethod.Invoke(wss.SoapExtensionTypes, null);
   MethodInfo setReadOnlyMethod = typeof(System.Configuration.ConfigurationElement).GetMethod("SetReadOnly", BindingFlags.NonPublic | BindingFlags.Instance);
   setReadOnlyMethod.Invoke(wss.SoapExtensionTypes, null);
}