IronPython 2.7.4公开应用程序对象模型

我正在尝试从IronPython文档中运行基本的托管"Exposing Application Object Model"C#示例。范围SetVariable（…）似乎不足以公开方法。对象已公开，但无法访问其方法。以下适用于旧的IronPython 1。

using System;
using IronPython.Hosting;
public class CallingDotNet {
    private static void Main(string[] args) {
        var engine = Python.CreateEngine();
        var scope = engine.CreateScope();
        scope.SetVariable("my_object_model", new CallingDotNet());
        engine.CreateScriptSourceFromString("my_object_model.Foo(42)").Execute(scope);
    }
    public void Foo(int arg) {
        Console.WriteLine("You gave me a {0}", arg);
    }
}

获得以下异常wwith IronPython 2.7:

'CallingDotNet' object has no attribute 'Foo'
   at IronPython.Runtime.Binding.PythonGetMemberBinder.FastErrorGet`1.GetError(CallSite site, TSelfType target, CodeContext context)
   at System.Dynamic.UpdateDelegates.UpdateAndExecute2[T0,T1,TRet](CallSite site, T0 arg0, T1 arg1)
   at Microsoft.Scripting.Interpreter.DynamicInstruction`3.Run(InterpretedFrame frame)
   at Microsoft.Scripting.Interpreter.Interpreter.Run(InterpretedFrame frame)
   at Microsoft.Scripting.Interpreter.LightLambda.Run2[T0,T1,TRet](T0 arg0, T1 arg1)
   at IronPython.Compiler.PythonScriptCode.RunWorker(CodeContext ctx)
   at IronPython.Compiler.PythonScriptCode.Run(Scope scope)
   at IronPython.Compiler.RuntimeScriptCode.InvokeTarget(Scope scope)
   at IronPython.Compiler.RuntimeScriptCode.Run(Scope scope)
   at Microsoft.Scripting.SourceUnit.Execute(Scope scope)

那么，我应该如何使用IronPython 2.7公开对象呢？

编辑：事实上，我正在尝试运行以下代码，我想我对名称空间/导入感到困惑：

using System;
using IronPython.Hosting;
namespace IronTestHosting
{
    class Program
    {
        public class CallingDotNet
        {
            public static void Run(string[] args)
            {
                var engine = Python.CreateEngine();
                var scope = engine.CreateScope();
                scope.SetVariable("my_object_model", new CallingDotNet());
                engine.CreateScriptSourceFromString("my_object_model.Foo(42)").Execute(scope);
            }
            public void Foo(int arg)
            {
                Console.WriteLine("You gave me a {0}", arg);
            }
        }        
        static void Main(string[] args)
        {
            CallingDotNet.Run(args);
            Console.ReadLine();
        }
    }
}