The process of extracting the bounce animation is a little more complicated than the process of extracting the contact-fetching code. The purpose of extracting this bounce animation is to make it so that it becomes possible to make other objects in other sections of the app bounce, just like the contact cell's image does.
To figure out what the bounce animation helper should do and how it should work, it's a great idea to think about how you want to use this helper at the call site. The call site is defined as the place where you plan to use your helper. So, in this case, the call site is considered the ViewController. Let's write some pseudocode to try to determine what you will program later:
let onBounceComplete ...
