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

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

        
        let delegate = WTURLSessionDelegate()
        delegate.completionHandler = completionHandler
        
        delegate.credential = credential
        let configuration = URLSessionConfiguration.default
        configuration.urlCache = URLCache.sharedURLCacheForRequests()
