Elastica\Client::_prepareConnectionParams PHP Method

    protected function _prepareConnectionParams(array $config)
    {
        $params = [];
        $params['config'] = [];
        foreach ($config as $key => $value) {
            if (in_array($key, ['bigintConversion', 'curl', 'headers', 'url'])) {
                $params['config'][$key] = $value;
            } else {
                $params[$key] = $value;
            }
        }
        return $params;
    }