protected function applyAutoEagerLoading($fetch = 'unit') {
        if (! empty($this->eagerLoad)) {
            return;
        }

        if ($this->enableAutoEagerLoading && $fetch == 'unit') {
            $this->eagerLoad = $this->model->unitRelations();
        }

        elseif ($this->enableAutoEagerLoading && $fetch == 'list') {
            $this->eagerLoad = $this->model->listRelations();
        }
    }