iOS 10 offers a new way to prefetch items before they are visible in the actual visible area. This allows the developer to be notified when items are fetched so he/she can react on that beforehand (e.g. for preloading images already).
The indexPaths are ordered ascending by geometric distance from the table view
Along with that, the user can also be notified when items that previously qualified for prefetching were not actually displayed. For both cases, we can expose them using the events prefetch and cancelprefetch.