         let delegate = WTURLSessionDelegate()
         delegate.completionHandler = completionHandler
         delegate.credential = credential
-        delegate.shouldCache = true
+        
         
         let configuration = URLSessionConfiguration.default
 //        configuration.urlCache = URLCache.sharedURLCacheForRequests()

    
    public func urlSession(_ session: URLSession, dataTask: URLSessionDataTask, willCacheResponse proposedResponse: CachedURLResponse, completionHandler: (CachedURLResponse?) -> Swift.Void){
        if self.error == nil {
            if shouldCache {
                completionHandler(proposedResponse)
                return
            }

    
    
    private static let sharedInstance = WTURLSessionDelegate()
    
    //网址凭据
    var credential: URLCredential?
