private function buildSortParameter() {
        $parameter = new Swagger\Parameter();
        $parameter->setName('sort');
        $parameter->setDescription(
            'Any field on the model can be a sort field. The sort can contain multiple fields, comma separated.
			It is also possible to get a reverse sort by adding a - in front of the field . Optional.'
        );
        $parameter->setParamType('query');
        $parameter->setType('string');

        return $parameter;
    }