protected static function getRequestRelationships($parameters)
    {
        //work with objects
        if (!is_object($parameters) && is_array($parameters)) {
            $parameters = (object) $parameters;
        }

        //Require data
        Request::requireParameters($parameters, ['data']);

        //Require data['relationships']
        if (isset($parameters->data->relationships)) {
            return (object) $parameters->data->relationships;
        } else {
            return new \stdClass();
        }
    }