void Object::defineDefaultProperty(const StringRef name, ReturnedValue (*code)(CallContext *), int argumentCount)
{
    ExecutionEngine *e = engine();
    Scope scope(e);
    Scoped<FunctionObject> function(scope, e->newBuiltinFunction(e->rootContext, name, code));
    function->defineReadonlyProperty(e->id_length, Primitive::fromInt32(argumentCount));
    defineDefaultProperty(name, function);
}