public function getModel()
    {
        if (!$this->model) {
            $this->model = $this->add($this->model_name);
        }
        /** @type Model $this->model */
        if ($this->display_field) {
            $this->model->title_field = $this->display_field;
        }
        if ($this->table_alias) {
            $this->model->table_alias = $this->table_alias;
        }

        return $this->model;
    }