Swift and Obj-C dataTask API.swift

// Obj-C
- (NSURLSessionDataTask *)dataTaskWithURL:(NSURL *)
                     urlcompletionHandler:(void (^)(
                                                    NSData * _Nullable data,
                                                    NSURLResponse * _Nullable response,
                                                    NSError * _Nullable error)
                                                   )completionHandler;

// Swift
func dataTask(
    with url: URL,
    completionHandler: @escaping (Data?, URLResponse?, Error?) -> Void
) -> URLSessionDataTask