public function getFormData($field = null)
    {
        $filters = session('bzarzuela.filters');

        if (isset($filters[$this->key]['form_data'])) {

            if (! is_null($field)) {

                if (! isset($filters[$this->key]['form_data'][$field])) {
                    return null;
                }

                return $filters[$this->key]['form_data'][$field];
            }

            return $filters[$this->key]['form_data'];
        }

        if (! is_null($field)) {
            return null;
        }

        return [];
    }