对于非常特定的字符串，dataTaskWithRequest需要太长时间

I'm creating an IOS app using swift. Recently, I've encountered a weird bug. Im trying to check if a url is valid, therefore, I'm creating a request with the url and check for the response. I do this task with dataTaskWithRequest of NSUrlSession. The weird bug is that if the URL is I'm creating an IOS app using swift. Recently,