private function prepareData($params = [], $options = [])
    {
        if(array_get($options, 'content_type') == "json") {
            $data['json'] = $params; // pass data as array which gets json_encoded
        } else {
            $data['query'] = $this->prepareQueryString($params); // pass data as query string
        }

        return array_merge($data, $options);
    }