      这里的task和data是私有的,原因在于不允许外界修改,想要得到原始的task只需要调用otigintask就可以了
      */
     //原始的task
-    private var task: URLSessionTask
+    open var task: URLSessionTask
     //懒加载,需要的时候创建对象
-    private lazy var data:Data = Data()
-    private var error: Error?
+    open lazy var data:Data = Data()
+    open var error: Error?
     
     
     init(task: URLSessionTask) {

extension WTURLSessionManager:URLSessionDataDelegate{
    
    public func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, didReceive response: URLResponse, completionHandler: @escaping (URLSession.ResponseDisposition) -> Swift.Void){
        if let task = self[dataTask] {
            task.urlSession(session, dataTask: dataTask, didReceive: response, completionHandler: completionHandler)
        }else{
            completionHandler(URLSession.ResponseDisposition.allow)

    public func urlSession(_ session: URLSession, downloadTask: URLSessionDownloadTask, didResumeAtOffset fileOffset: Int64, expectedTotalBytes: Int64){
        
    }
}
open class WTURLSessionUploadTask:WTURLSessionTask{

}

open class WTURLSessionManager:NSObject{
    
