static Handle<Value> TracedGetProperty(Local<String> property, const AccessorInfo &info)
{
    HandleScope scope;
    String::AsciiValue property_name(property);
    if(strcmp(*property_name, "createElement"))
        cerr << "prop: " << *property_name << endl;
    return Handle<Value>();
}

// called when a TracedObject is constructed
static Handle<Value> TracedObjectCallback(const Arguments &args)
{
    HandleScope scope;
    assert(args.Data()->IsFunction());
    static Persistent<ObjectTemplate> traced_obj;
    if(traced_obj.IsEmpty()) {
        traced_obj = Persistent<ObjectTemplate>::New(ObjectTemplate::New());
        traced_obj->SetNamedPropertyHandler(TracedGetProperty);
    }
    Handle<Object> result = traced_obj->NewInstance();
    Handle<Function> constructor = Handle<Function>::Cast(args.Data());
    vector<Handle<Value> > argvals;
    for(int i=0; i < args.Length(); ++i) argvals.push_back(args[i]);
    constructor->Call(result, argvals.size(), &argvals[0]);
    return scope.Close(result);
}

static Handle<Value> TracedObject(const Arguments &args)
{
    if(args.Length() != 1 || !args[0]->IsFunction()) return v8::Undefined();
    HandleScope scope;
    Handle<Function> constructor = Handle<Function>::Cast(args[0]);
    Handle<FunctionTemplate> func = FunctionTemplate::New(TracedObjectCallback, constructor);
    Handle<Function> result = func->GetFunction();
    //result->Set(String::New("prototype"), constructor->Get(String::New("prototype")));
    return scope.Close(result);
}