     public func detectFaces(
         imagesFile: URL? = nil,
         url: String? = nil,
+        acceptLanguage: String? = nil,
         imagesFileContentType: String? = nil,
         headers: [String: String]? = nil,
         completionHandler: @escaping (WatsonResponse<DetectedFaces>?, WatsonError?) -> Void)

       recommended pixel density is 32X32 pixels per inch, and the maximum image size is 10 MB. Redirects are followed,
       so you can use a shortened URL.
       You can also include images with the **images_file** parameter.
     - parameter imagesFileContentType: The content type of imagesFile.
     - parameter headers: A dictionary of request headers to be sent with this request.
     - parameter completionHandler: A function executed when the request completes with a successful result or error

        }
        headerParameters["Accept"] = "application/json"
        headerParameters["Content-Type"] = multipartFormData.contentType
        if let acceptLanguage = acceptLanguage {
            headerParameters["Accept-Language"] = acceptLanguage
        }

        // construct query parameters
        var queryParameters = [URLQueryItem]()
