may I know how I can save it to file? RingCentral\SDK\Http\ApiResponse Object ( [_jsonAsArray:protected] => [_jsonAsObject:protected] => [_multiparts:protected] => [_response:protected] => GuzzleHttp\Psr7\Response Object ( [reasonPhrase:GuzzleHttp\Psr7\Response:private] => OK [statusCode:GuzzleHttp\Psr7\Response:private] => 200 [headers:GuzzleHttp\Psr7\Response:private] => Array (