RequestMethod.swift

func request(_ url: String, method: HTTPMethod = .get, parameters: Parameters? = nil,
             encoding: ParameterEncoding = URLEncoding.queryString, headers: HTTPHeaders? = nil,
             interceptor: RequestInterceptor? = nil, completion: @escaping completionHandler) {
    AF.request(url, method: method, parameters: parameters, encoding: encoding,
               headers: headers, interceptor: interceptor ?? self).validate().responseJSON { (response) in
        if let data = response.data {
            completion(.success(data))
        } else {
            completion(.failure(.unavailableServer))
        }
    }
}