对于Swift中的Apple Watch OS，如何在WCSession激活完成后运行函数？

I have a method in my main interface controller class that I wish to run when the WCSession between the phone and watch has finished activating. I know there is a didFinishActivation function in the WCSession class. However, how do I communicate the result of this function to my main interface controller class to run the function in there, after WCSession has finished activating?I have a method in my main interface controller