public function routeModel($key)
    {
        if (! isset($this->routeModels[$key])) {
            $Clazz = Inflector::classify($key);

            $collection = Norm::factory($this->schema($key)->get('foreign'));

            $this->routeModels[$key] = $collection->findOne($this->routeData($key));
        }

        return $this->routeModels[$key];
    }