Question: I want to know from which source and medium the current request is coming, when the user clicks on the signup button. On the server side, I am using .NET MVC.

I don't know how to use \_utmZ cookie and retrieve data from it.

I tried using analytics.js but I cant find campaign, source and medium.

Answer: 
With your version, the following will not compile:

```
class Base implements Comparable<Base> { ... }

class Derived extends Base { ... }

List<Derived> list = ...;

mySort(list);

```

`Derived` does **not** extend `Comparable<Derived>`. However, it does extend `Comparable<Base>` (and thus, `Comparable<? super Derived>`).
From what I understood, "<? super T>" is a way to recognize that the CompareTo method is not implemented in T itself, but inherited by a SuperClass.