gistfile1.txt

    private func fetch(credentials: Credentials, inEntityNamed: String, url: String, _ completion: @escaping (NSError?) -> Void) {
        //print("Authentication: '\(credentials.user)' '\(credentials.password)'")
        Alamofire
            .request(url)
            .authenticate(user: credentials.user, password: credentials.password)
            .responseData { response in
                let statusCode = response.response?.statusCode
                
                if 200 <= statusCode! && statusCode! <= 299 {
                    let jsonResult = Request.serializeResponseJSON(options: JSONSerialization.ReadingOptions.allowFragments, response: response.response, data: response.data, error: nil)
                    
                    switch jsonResult {
                        
                    case .success(let json):
                        let changes = json as! [[String: Any]]
                        
                        Sync.changes(changes, inEntityNamed: inEntityNamed, dataStack: self.dataStack) { error in
                            completion(error)
                        }
                        
                    case .failure(let error):
                        print(error)
                        
                    }
                } else if (statusCode! == 401) {
                    print("Authentication error")
                } else {
                    print("Error (HTTP Status Code \(statusCode)")
                }
        }
    }