        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 acceptLanguage: The desired language of parts of the response. See the response for details.
      - 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

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

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

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