public function source($source = null)
    {
        $model = $this->noInitModel;
        if (!is_string($model->sourceAttribute)) {
            return $this;
        }
        if (!is_string($source)) {
            $modelClass = $this->modelClass;
            $source = $modelClass::$sourceSelf;
        }
        return $this->andWhere([$model->sourceAttribute => $source]);
    }