     public var progressHandler:progressHandler?
     public var response:URLResponse?
     public var challengeHandler:challengeHandler?
-    
+    public var useRequestingIfHave:Bool = false
     public var originTask:URLSessionTask{
         get{
             return task;

extension URLSession{
    
    
    private static func wt_sharedInstance()->URLSession{
        let delegate = WTURLSessionDelegate.sharedInstance
        let configuration = URLSessionConfiguration.default
        configuration.urlCache = URLCache.wt_sharedURLCacheForRequests()

    }
    
    public func resume(){
        if useRequestingIfHave {
            
        }
        task.resume()
    }
    public func suspend(){
